Cells-The Living Units
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| organisms arise spontaneously from garbage or other nonliving matter | theory of spontaneous generation
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| when define cell properties are defining | properties of life
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| activity of organism depends on both individual and collective | activities of its cells
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| biochemical activities of cells are dictated by relative number of their specific subcellular structures | principle of complementarity of structure and function
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| not highly differentiated biologically nor strictly adapted to a particular environment | generalized cells
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| specialized cells are considered | composite cells
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| fragile barrier; composed of phospholipids, cholesterol, & proteins; encloses cell contents; outer limiting cell membrane | plasma membrane
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| internal to plasma membrane; intracellular fluid packed with organelles, small structures that perform specific functions | cytoplasm
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| controls cellular activities & typically lies near cell's center | nucleus
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| depiction of membrane (7-10nm) structure of cell, as phospholipid bilayers in which proteins are dispersed | fluid mosaic model
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| many proteins, of plasma membrane, float in __ __ __, forming constantly changing mosaic patterns | fluid lipid bilayer
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| forms basic fabric of plasma membrane; constructed largely of phosolipids with smaller amount of cholesterol & glycolipids | lipid bilayer
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| refers to molecules, or portions of molecules, that interact with water and charged particles; lollipop-shaped phospholipid | hydrophilic
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| refers to molecules, or portions of molecules, that interact only with uncharged, nonpolar molecules; made of two fatty acid chains | hydrophobic
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| each lollipop-shaped __ has hydrophilic & __ that is hydrophobic | head; tail
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| hydrophilic polar heads are attracted to inner & outer surfaces of plasma membrane, because main constituent of both | intracellular & extracellular fluid
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| hydrophobic, nonpolar tails line up in __ of membrane | center
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| property of phospholipids encourages biological membranes to self-assemble into closed, generally spherical, structures and reseal themselves quickly when torn | self-orienting
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| plasma membrane is __ __ structure in constant flux | dynamic fluid
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| lipid molecules of bilayer move freely __ __ membrane surface, side to side | parallel
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| __ __ prevent lipid molecules from flip-flopping or moving from one phospholipid layer to other | nonpolar interactions
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| differ in kinds and amounts of lipids they contain; variations important in determining local membrane structure & function | inward- facing & outward-facing surfaces
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| majority of membrane phospholipids are __, condition which kins their tails (increasing space btwn them) & increases membrane fluidity | unsaturated
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| lipid with one or more covalently attached sugars | glycolipids
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| glycolipids are found only on __ plasma membrane surface, accounting for about 5% of total membrane lipid | outer
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| sugar groups of glycolipid make that end of the molecule __, whereas __ __ tails are nonpolar | polar; fatty acid
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| hydroxyl group of cholesterol is __ region and its fused ring system is __ region | polar; nonpolar
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| cholesterol wedges its platelike __ __ btwn phospholipid tails, __ membrane while increasing __ of phospholipid & fluidity of membrane | hydrocarbon rings; stabilizing; mobility
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| contained in outer membrane surface, 20%; dynamic assemblies of saturated phospholipids associated w/unique lipids called sphingolipids & lots of cholesterols | lipid rafts
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| lipid rafts are __ __ and orderly, less fluid than rest of membrane, & can include/exclude specific __ to various extents | more stable; proteins
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| lipid rafts are assumed to be __ __ for certain receptor molecules or for molecules needed for cell signaling | concentrating platforms
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| make up about 1/2 of plasma membrane by mass & are responsible for most of specialized membrane functions | proteins
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| firmly inserted into lipid bilayer have both hydrophobic & hydrophilic regions allowing them to interact both w/nonpolar lipid tails buried in membrane & w/water inside/outside cell | integral proteins
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| some integral proteins __ from one face only | protrude
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| most integral proteins, that span entire width of membrane & protrude on both sides | transmembrane proteins
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| most __ proteins are involved in transport, although some are __ | transmembrane; enzymes
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| some transmembrane proteins cluster together forming __/__, through which small, water-soluble molecules/ions can move | channels; pores
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| when transmembrane proteins form channels, allowing small, water-soluble molecules/ions to pass it bypasses the __ __ of membrane | lipid part
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| __ __ __ act as carriers that bind to substance & then move it through membrane | some transmembrane proteins
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| some transmembrane proteins are receptors for hormones or other chemical messengers & relay messages to cell interior; process is called | signal transduction
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| related to, located in, or constituting an outer boundary; attach rather loosely only to integral proteins & are easily removed w/out disrupting membrane | peripheral proteins
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| peripheral proteins include network of __ that help support membrane from cytoplasmic side | filaments
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| some __ proteins are enzymes | peripheral
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| some peripheral proteins are __ proteins involved in mechanical functions, i.e. changing cell shape during cell division & muscle cell contraction | motor
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| some proteins float freely, but in particular peripheral proteins are __ in their movements because they are tethered to intracellular structures that make up __ | restricted; cytoskeleton
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| many of proteins that abut extracellular fluid are __ w/branching sugar groups | glycoproteins
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| glycocalyx is layer of __ facing glycoproteins on cell's plasma membrane that determines __ __ | externally; blood type
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| glycocalyx involved in cellular interactions of fertilization, embryonic development, & immunity; acts as adhesive btwn cells | glycocalyx
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| term glycocalyx means | sugar covering
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| glycocalyx used to describe fuzzy, sticky, __ area at cell surface | carbohydrate-rich
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| glycocalyx that clings to each cell's surface is enriched by __ & __ secreted by cell | glycolipids; glycoproteins
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| glycocalyx provides highly specific __ __ by which approaching cells recognize each other | biological markers
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| cell of immune system identify __ by binding to certain membrane glycoproteins in __ glycocalyx | bacterium; bacterial
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| cancer cell's glycocalyx may change continuously, allowing it to keep ahead of immune system __ mechanism and avoid __; example of homeostatic imbalance | recognition; destruction
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| glycoproteins in glycocalyx, wavy contours of membranes adjacent cells (tongue-&-groove fashion), & special membrane junctions formed are three factors that | act to bind cell together
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| most important factor securing cells together are | junctions
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| area where plasma membranes of adjacent cells are fused; series of integral protein molecules in plasma membranes of adjacent cells | tight junctions
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| series of integral proteins molecules in tight junctions include | occludins & claudins
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| when series of integral proteins molecules, in tight junctions, fuse together they form __ junctions that encircle cell | impermeable
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| tight junctions help prevent molecules from from passing through __ __ btwn adjacent cell | extracellular space
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| although called impermeable junctions, some tight junctions __ & may allow certain types of ions to __ | leak; pass
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| cell junction composed of thickened plasma membranes joined by filaments; binding bodies; anchoring junctions | desmosomes
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| mechanical couplings scattered like rivets along sides of abutting cells that prevent their separation | anchoring junctions
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| button-like thickening on cytoplasmic face of each plasma membrane | plaque
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| thin linker protein filaments that extend from plaques & fit together with adjacent cells, like teeth of a zipper in intercellular space | cadherins
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| intermediate filaments forming past of cytoskeleton | keratin filaments
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| keratin filaments, of desmosomes, extend from __ side of plaque across width of cell to anchor plaque on cell's opposite side | cytoplasmic
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| desmosomes not only bind neighboring cells together, but also contribute to continuous __ __ of strong "guy-wires" | internal network
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| arrangement of desmosomes continuous internal network, distributes __ throughout cellular sheet & reduces chance of tearing when subject to pulling forces | tension
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| desmosomes are abundant in tissues subjected to great __ __, such as skin & heart muscle | mechanical stress
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| communicating junction/passageway between 2 adjacent cells; formed by transmembrane proteins called connexons | gap junction
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| hemichannel supplied by 1 protein cell, on 1 side of gap junction; | connexon
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| assembly of six protein hemichannels, supplied by cell on 1 side of gap junction | connexin
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| ions, simple sugars, & other small molecules pass through water-filled channels from 1 cell to next, acting as conduit btwn cytoplasm & extracellular space | connexon/connexin
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| gap junctions are present in __ __ tissues, where ion passage from cell to cell helps __ their electrical activity & contraction | electrically excitable; synchronize
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| fluid between the cells; derived from blood; contains amino acids, sugars, fatty acids, vitamins, regulatory hormones, neurotransmitters, salts & waste products | interstitial fluid (IF)
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| to stay healthy each cell must __ from the IF exact amounts of substance it needs at specific times | extract
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| allows some substance to pass while excluding others; keeps undesirable substance out while allowing nutrients in; keeps valuable cell proteins & other substance in cell, but allows waste out | selectively/differentially permeable membrane
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| substances cross membrane without any energy input from cell | passive process
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| membrane transport processes for which ATP is required, e.g., solute pumping and endocytosis | active process
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| characteristic of healthy, intact cells | selective permeability
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| when cell/plasma membrane severely dmgd, membrane becomes __ to virtually everything and substance flow into/out of cell freely; causes homeostatic imbalance | permeable
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| when someone is severely burned, precious fluids, proteins, and ions, "weep" from dead & dmgd cells; this is an example of a(n) __ __ membrane becoming a(n) __ membrane | selectively permeable; permeable
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| diffusion & filtration; two main types of __ transport | passive
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| spreading of particles in gas or solution w/movement toward uniform distribution of particles | diffusion
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| diffusion is tendency of molecules/ions to move from area where they are in __ concentration to area where they are in __ concentration | higher; lower
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| difference in the concentration of a particular substance between two different areas | concentration gradient
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| greater difference in concentration of diffusing molecules and ions btwn 2 areas, more collisions occur & faster __ __ of particles | net diffusion
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| driving force of diffusion is | kinetic energy
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| speed of diffusion is influenced by molecular __ & __ | size; temperature
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| in a closed container, diffusion eventually reaches equilibrium, with molecules moving equally in all directions causing a __ __ of molecules | uniform mixture
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| movement of ions across cell membranes & movement of neurotransmitters btwn two nerve cells | examples of diffusion
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| __ __ is almost impossible to see | pure diffusion
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| plasma membrane is physical barrier to free diffusion because of its | hydrophobic core
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| molecule will diffuse through membrane if molecule is __ __ | lipid soluble
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| molecule will diffuse through membrane if molecule is small enough to | pass through membrane channels
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| molecule will diffuse through membrane if molecule is assisted by a(n) __ __ | carrier molecule
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| unassisted diffusion of lipid-soluble molecules or very small particles | simple diffusion
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| unassisted diffusion of solvent (usually water) through a selectively permeable membrane | osmosis
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| assisted diffusion is known as | facilitated diffusion
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| in simple diffusion, these substances diffuse directly through the lipid bilayer; these incl oxygen, carbon dioxide, & fat-soluble vitamins | nonpolar & lipid-soluble substances
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| oxygen concentration is always higher in blood than in tissues, therefore oxygen always diffuses __ __ __ from blood to tissue | down concentration gradient
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| carbon dioxide is in higher concentration within tissues than blood, therefore it diffuses __ __ __ from tissue into blood | down concentration gradient
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| glucose/other sugars, some amino acids, & ions are unable to pass through lipid bilayer, therefore passive process of __ diffusion | facilitated
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| facilitated diffusion, allows substance unable to pass through lipid bilayer, to be transported by binding to __ __ in membrane that ferries them across | protein carriers
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| facilitated diffusion, allows substance unable to pass through lipid bilayer, to be transported by moving through water-filled __ __ | protein channels
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| transmembrane integral protein that shows specificity for molecules of certain polar substance/class of substances, too lrg to pass through membrane channels; i.e. sugars & amino acids | carriers
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| most popular model for action of carriers, indicates change in shape of carrier allowing it to envelop & then release substance, shielding it en route from | non polar regions of membrane
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| __ __, of carriers, is moved from one face of membrane to other by changes in conformation of carrier protein | binding site
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| one of spatial arrangements of atoms in molecule that can come about through free rotation of atoms about single chemical bond | conformation
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| glucose moves down its concentration gradient, just as in simple diffusion, when transported by __ __ diffusion | carrier-mediated facilitated
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| normally in higher concentration in blood than in cells, where its rapidly used for ATP synthesis | glucose
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| glucose transport within body is typically __, into the cells | unidirectional
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| limited by numbers of protein carrier present | carrier-mediated transport
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| when all glucose, carrier-mediated transport, carriers are __ they are said to be saturated & glucose transport is occurring at __ __ | engaged; maximum rate
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| transmembrane protein that forms aqueous pore, allowing substances to move from one side of membrane to other | channels
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| exist within channels, and channels are selective due to pore size and charges of amino acids lining channel | binding/association sites
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| channels always open & simply allow ion/water fluxes according to concentration gradients | leakage channels
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| some channels are gated & controlled, __ or __, by various chemical or electrical signals | open; closed
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| many channels can be inhibited by certain molecules, show __, and tend to be specific | saturation
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| substances moving through channels also follow the concentration gradient, always moving | down the gradient
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| when substance crosses membrane by simple diffusion, rate of diffusion is not controllable because __ __ of membrane is not immediately changeable | lipid solubility
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| rate of facilitated diffusion is __ because permeability of membrane can be altered by __ activity/number of individual carriers or channels | controllable; regulating
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| vitally important to cellular homeostasis; passive transport by diffusion, either simple/facilitated, represents tremendous saving of cellular energy | oxygen, water, glucose, & various ions
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| if oxygen, water, glucose, & various ions had to be transported __, cell expenditures of ATP would __ exponentially | actively; increase
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| even though water is highly polar, it passes via osmosis through __ __ | lipid bilayer
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| transmembrane proteins that form water channels | aquaporins (AQPs)
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| water moves freely & reversibly through __ __ constructed by AQPs | water-specific channels
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| AQPs are particularly abundant in RBCs & cells involved in __ __, such as kidney tubules | water balance
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| osmosis occurs whenever __ __ differs on 2 sides of membrane | water concentration
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| if distilled water present on both side of selectively permeable membrane, no __ __ occurs, even though water molecules move in both direction through membrane | net osmosis
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| solute concentration on 2 sides of membrane differs, water concentration __ | differs
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| extent to which water's concentration is decreased by solutes depends on __ not on __ of solute particles | number; type
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| one molecule or one ion of solute | displaces one water molecule
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| number of solute particles present in 1 liter of a solution | osmolarity
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| when equal volumes of aqueous solutions of different osmolarity are separated by membrane that is permeable to all molecules in system, net diffusion of __ occurs; each moving __ its concentration gradient | both; down
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| pressure of fluid in a system | hydrostatic pressure
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| measure of tendency of water to move into more concentrated solution | osmotic pressure
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| higher amount of nondiffusible, non penetrating, solutes in cell higher the __ pressure & greater __ pressure that must be developed to resist further net water entry | osmotic; hydrostatic
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| major changes in hydrostatic/osmotic pressure do not occur in living animal cells because they lack | rigid cell walls
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| cause animal cells to swell or shrink, due to net water gain/loss, until wither solute concentration is same on both side of membrane, or membrane is stretched to breaking point | osmotic imbalances
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| ability of solution to change shape/tone of cells by altering their internal water volume | tonicity
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| of, relating to, or exhibiting equal osmotic pressure | isotonic
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| cells exposed to __ __ retain their normal shape, & exhibit not net loss/gain of water | isotonic solutions
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| body's __ fluids & most __ solutions are isotonic | extracellular; intravenous
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| solutions with higher concentration of nonpenetrating solutes than seen in cell | hypertonic
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| cells immersed in __ __ lose water and shrink | hypertonic solutions
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| having the margin or surface cut into rounded scallops; effect of immersion in hypertonic solutions | crenate
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| solutions more dilute than cells | hypotonic
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| cells placed in __ __ plump up rapidly, as water rushes into them | hypotonic solutions
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| represents most extreme example of hypotonicity, because contains no solutes, water continues to enter cells until they finally burst | distilled water
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| bursting of a cell | lyse
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| tonicity is based on how solute affects cell volume, which depends on solute __ & solute __ of plasma membrane | concentration; permeability
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| osmolarity is expressed as __ per liter | osmoles
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| 1 osmole = to 1 mole of __ molecules | nonioniziting
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| osmosis is extremely important in determining distribution of water in various __ __ of body | fluid-containing compartments
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| osmosis continues until osmotic & hydrostatic pressure acting at membrane are | equal
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| water is forced out of capillary blood by __ pressure of blood against capillary wall, but presence in blood on solutes that are too lrg to cross capillary membrane draws water back into __; resulting in very little net loss of __ __ | hydrostatic; blood-stream; plasma fluid
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| simple diffusion & osmosis occurring directly through plasma membrane are not __ processes | selective
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| simple diffusion & osmosis occurring directly through plasma membrane, whether molecule can pass through membrane depends chiefly on __ or __ in lipid, not on its unique structure | size; solubility
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| facilitated diffusion is often __ __ | highly selective
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| hypotonic solutions are sometimes infused in edematous patients, to draw excess water out of __ __ and move it into __ so it can be eliminated in kidneys | extracellular space; bloodstream
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| hypotonic solutions may be use to __ __ of extremely dehydrated patients | rehydrate tissues
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| requires carrier proteins that combine specifically & reversibly with transported substance | active transport
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| enzyme-like protein carrier that mediates active transport of solutes, such as amino acids & ions, uphill against concentration gradients | solute pumps
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| solutes moved by solute pumps, most importantly ions such as | Na+, K+, & Ca2+
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| active transport processes are distinguished according to their | source of energy
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| energy to do work comes directly from hydrolysis of ATP | primary active transport
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| driven by indirectly by energy store in ionic gradients created by operation of primary active transport pumps | secondary active transport
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| secondary active transport systems are all __ __; that is, they move more than one substance at a time | coupled systems
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| if 2 transported substances, in 2ndary active transport system, are moved in same direction | symport system
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| in 2ndary active transport system, if transported substances wave to each other as they cross the membrane in opposite directions | antiport system
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| in primary active transport, hydrolysis of ATP results in __ of transport protein | phosphorylation
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| phosphorylation caused protein to change __ in such a manner that it __ bound solute across membrane | shape; pumps
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| incl calcium & hydrogen pumps, but most investigate example is operation of sodium-potassium pump | primary active transport systems
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| primary active transport system that simultaneously drives Na^+ out of cell against steep gradient & pumps K^+ back in | sodium-potassium pump
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| carrier enzyme in sodium-potassium pump | Na+-K+ ATPase
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| concentration in body cell is 10 times higher that outside | K+
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| concentration in body cell is 10 lower higher that outside | Na+
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| the __ __ __ of K+ vs Na+, are essential for excitable cells, like muscle & nerve cells, to function normally | ionic concentration difference
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| leak slowly but continuously through leakage channels in plasma membrane along their concentration gradient, & cross more rapidly in stimulated muscle & nerve cells | Na+ & K+
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| operates more/less continuously as an antiporter | Na+ -K+ pump
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| maintained by Na+ -K+ pump, underlie most primary & secondary active transport of nutrients & ions; crucial for cardiac & skeletal muscle & neuron functions | electrochemical gradients
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| can indirectly drive secondary active transport of several other solutes | single ATP-powered pump
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| by Na+ -K+ pump, moving sodium across plasma membrane against concentration gradient, pump __ __ in ion gradient | store energy
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| substance pumped uphill/against concentration gradient across membrane can __ __ as it leaks back - propelled downhill along its concentration gradient | do work
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| in Na+ -K+ pump: as sodium moves back downhill, into cell w/help of carrier proteins, other substance are __ by common carrier, a symport system | cotransported
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| both cotransported substances (in Na+ -K+ pump: as sodium moves back downhill) move __ because energy for this type of transport is concentration gradient of the ion | passively
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| can be used in symport systems, or used to drive antiport systems | ion gradients
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| sugars, amino acids, and many ions are cotransported into cells lining small intestines; this is example of | symport system in secondary active transport
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| regulation of intracellulare pH by using sodium gradient to expel hydrogen ions, is an example of | antiport system in secondary active transport
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| whether energy is provided directly, in primary active transport, or indirectly, in secondary active transport, each membrane pump/cotransporter transports __ __ substances | only; specific
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| because membrane pump/cotransporter transports only specific substances, active transport systems provide way for cell to be very __ in cases where substances cannot pass by __ | selective; diffusion
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| pocket of embryonic tissue that is beginning of an organ; membranous sac | vesicles
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| movement of large particles & macromolecules across a plasma membrane | vesicular transport
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| mechanism by which substances are moved from cell interior to extracellular space as secretory vesicle fuses w/plasma membrane | exocytosis
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| means by which fairly large extracellular molecules or particles enter cells, e.g., phagocytosis, pinocytosis, receptor-mediated endocytosis | endocytosis
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| moving substances into, across, & then out of cells | transcytosis
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| moving substances from one are/organelle in cell to another | substance/vesicular trafficking
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| vesicular transport processes are energized by __, or in some cases another energy-rich compound, GTP - guanosine triphosphate | ATP
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| all forms of vesicular transport involve assortments of __ vesicles of 3 types, with some exceptions, all are __ by membrane receptors | protein-coated; mediated
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| protein-coated vesicles provide main route for __ & __ of bulk solids, most macromolecules, & fluids | endocytosis; transcytosis
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| often hijacked by pathogens seeking entry into a cell | protein-coated vesicles
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| in endocytosis stage1, substance to be taken into cell progressively enclosed by infolding portion of plasma membrane called | coated pit
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| protein coating that forms on cytoplasmic side of coated pit, in endocytosis | clathrin
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| clathrin & some accessory proteins; acts both in cargo selection & in deforming membrane to produce vesicle | clathrin coat
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| in endocytosis stage2, vescile __ | detaches
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| in endocytosis stage 3, __ __ are recycled back to plasma membrane | coat proteins
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| in endocytosis stage4, __ __ then typically fuse with endosome | uncoated vesicle
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| processing and sorting vesicle | endosome
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| in endocytosis stage5, some membrane components & receptors of fused vescile may be recycled back to plasma membrane in __ __ | transport vesicle
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| in endocytosis stage6, remaining contents of vesicle may, __ with lysosome, or be transported completely across cell & released by __ on opposite side | combine; exocytosis
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| specialized cell structure containing digestive enzymes where digested substance is degraded or released | lysosome
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| transcytosis is common in __ cells lining blood vessels because it provides quick means to get substance from blood to interstitial fluid | endothelial
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| based on nature & quantity of material taken up & means of uptake, 3 types of endocytosis that use clathrin-coated vesicles are recognized | phagocytosis, pinocytosis, & receptor-mediated endocytosis
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| type of endocytosis in which cell engulfs relatively lrg/solid material; e.g. bacteria, dead cell debris, foreign substances engulfed by cells | phagocytosis
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|
||||
| in phagocytosis, when particle binds to receptors on cell's surface, __ __called pseudopods form & flow around particle & engulf it | cytoplasmic extensions
🗑
|
||||
| formed as a result of phagocytosis; vesicle containing engulfed material that fuses w/lysosome & its contents are digested | phagosome
🗑
|
||||
| in most cases phagosome fuses with __ & its contents are digested | lysosome
🗑
|
||||
| in human body, macrophages & certain WBCs are only cells that are experts at phagocytosis, called | phagocytes
🗑
|
||||
| flowing movement of the cytoplasm, into temporary pseudopods, of a phagocyte allowing them to creep along; "changing shape" | amoeboid motion
🗑
|
||||
| cells have the same __ parts | basic
🗑
|
||||
| plasma membrane, cytoplasm, nucleus, are all | basic parts of cells
🗑
|
||||
| cell membrane lipid bilayer w/proteins dispersed in it meaning it is a(n) | phospholipids bilayer
🗑
|
||||
| in cell membrane, __ float in the lipid bilayer | proteins
🗑
|
||||
| __ recognizes an ovum by its glycocalyx | sperm
🗑
|
||||
| glycocalyx forms cell __ molecules & __ | adhesion; receptors
🗑
|
||||
| transport, receptors, forming cell junctions are all functions of | membrane proteins
🗑
|
||||
| function of membrane proteins includes __ __ (glycocalyx) | cell-cell recognition
🗑
|
||||
| function of membrane proteins includes attaching to cytoskeleton & extracellular matrix to | help maintain cell shape
🗑
|
||||
| minute finger-like extensions of plasma membrane | microvilli
🗑
|
||||
| microvilli are example of __ of plasma membrane | specialization
🗑
|
||||
| microvilli increase __ __ | surface area
🗑
|
||||
| microvilli are found on __ __ i.e. kidney tubule cells & small intestinal cells | absorptive cells
🗑
|
||||
| example of desmosomes are | heart muscle cells
🗑
|
||||
| example of gap junctions are | heart muscle, smooth muscle
🗑
|
||||
| example of tight junctions are between epithelial lining of | digestive tract
🗑
|
||||
| lipids, CO2, O2 pass through plasma membrane via | simple diffusion
🗑
|
||||
| glucose, amino acids pass through plasma membrane via protein specific carrier in | carrier-mediated facilitated diffusion
🗑
|
||||
| vesicular transport requires | ATP
🗑
|
||||
| used for hormone, secretion, neurotransmitter release, mucous secretion | exocytosis
🗑
|
||||
| infolding plasma membrane pinches off droplet of extra cellular fluid & dissolved molecules- vesicle fuses w/endosome; occurs in most cells, esp. cells of intestines | pinocytosis
🗑
|
||||
| pinocytosis means | cell drinking
🗑
|
||||
| main mechanism for endocytosis & transcytosis of most macromolecules; substances bind to specific receptors on plasma membrane, vesicle formed; used for taking in some enzymes, hormones, cholesterol attaches to lipoproteins | receptor-mediated endocytosis
🗑
|
||||
| phagosome fuse with | lysosome
🗑
|
||||
| phagocytosis is process used by __ & __ to protect body | macrophages; neutrophils
🗑
|
||||
| exist across membranes of all cells of the body, resulting from separation of oppositely charged ions across membrane | electrical potential/voltage
🗑
|
||||
| in resting state cells have resting membrane __ ranging from 50-100 mV | potential
🗑
|
||||
| important in excitable tissues, such as nerve/muscle cells, where rapid changes are used to transmit impulses; typically ranges from -50 to -100 mV depending on cell type | resting membrane potential
🗑
|
||||
| resting membrane potential can also be considered | action potentials
🗑
|
||||
| the ionic concentration difference of K+ vs Na+, are essential for excitable cells, like muscle & nerve cells, for all body cells to maintain their normal __ __ | fluid volume
🗑
|
||||
| resting membrane potential is created by concentration of K+ more __ cells while that of Na+ is more __ cells | inside; outside
🗑
|
||||
| in __ membrane __, main factor is movement of K+ from inside to outside cell through leak channels (down concentration gradient) creating an electronegativity inside | resting; potential
🗑
|
||||
| in resting membrane potential, some diffusion of Na+ from outside-inside hardly makes difference to electronegativity because __ __ are 100x more permeable to K+ under resting conditions | leak channels
🗑
|
||||
| pumps out 3 Na+ for every 2 K+ pumped in; resulting in further loss of +charge from inside membrane, adding to electronegativity | Na+- K+ pump
🗑
|
||||
| have specificity for particular ligands; i.e., hormones, neurotransmitters | membrane receptor proteins
🗑
|
||||
| signaling chemicals that bind specifically to membrane receptors; most hormones, neurotransmitters, & paracrines | ligands
🗑
|
||||
| in membrane receptor, __ __ initiates specific/multiple cellular responses | ligand binding
🗑
|
||||
| common type of membrane receptors are G __ receptors | protein-linked
🗑
|
||||
| exert their effect indirectly through G proteins, which acts as middleman/relay to activate/inactivate membrane-bound enzyme/ion channel | G protein-linked receptors
🗑
|
||||
| cellular material surrounding the nucleus & enclosed by plasma membrane; contains the cytosol, organelles & inclusions | cytoplasm
🗑
|
||||
| largely water w/dissolved protein, salts, sugars, & other solutes | cytosol
🗑
|
||||
| mitochondria, peroxisomes, lysosomes, rough/smooth ER, & Golgi apparatus | membranous cytoplasmic organelles
🗑
|
||||
| cytoskeleton, centrioles, & ribosomes | nonmembranous cytoplasmic organelles
🗑
|
||||
| double membrane structure w/shelf-like cristae | mitochondria
🗑
|
||||
| mitochondria are __ __ in metabolically active cells like kidney/liver | more numerous
🗑
|
||||
| mitochondria contain __ __ DNA/RNA | their own
🗑
|
||||
| mitochondria provide majority of a cell's ATP via __ cellular respiration | aerobic
🗑
|
||||
| sites of protein synthesis; composed of proteins & rRNA; each has 2 subunits | ribosomes
🗑
|
||||
| __ __ synthesize soluble proteins | free ribosomes
🗑
|
||||
| located on RER; synthesize proteins to be incorporated into cells membranes/for export | membrane-bound ribosomes
🗑
|
||||
| system of interconnected tubes & parallel membranes enclosing cristae; is continuous w/nuclear membrane | endoplasmic reticulum
🗑
|
||||
| external surface studded w/ribosomes; manufacture all secreted proteins & proteins for cell membranes | Rough ER
🗑
|
||||
| RER __ __ in antibody producing plasma cells, secretory cells (pancreatic cells), liver cells which product plasma proteins | more abundant
🗑
|
||||
| enzymes of __ involved with lipid metabolism & cholesterol synthesis breakdown of glycogen (liver) | SER
🗑
|
||||
| enzymes of SER involved with synthesis of __ __, e.g. testosterone in testes | steroid-based hormones
🗑
|
||||
| enzymes of SER involved with __ reticulum in skeletal & cardiac muscle cells | sarcoplasmic
🗑
|
||||
| enzymes of SER involved with __ of drugs (liver & kidneys), | detoxification
🗑
|
||||
| role of calcium ion storage & release in muscle contraction, in skeletal & cardiac muscles | sarcoplasmic reticulum
🗑
|
||||
| stacked, flattened membranous sacs & tiny vesicles; functions in modification & packaging of proteins | Golgi apparatus
🗑
|
||||
| when transport vesicles from RER fuse w/Golgi apparatus, proteins are __ | modified
🗑
|
||||
| Golgi apparatus - proteins __ in vesicles, secretory vesicles move to plasma membrane, then are __ by exocytosis | packaged; discharged
🗑
|
||||
| spherical membranous bags of digestive enzymes (acid hydrolases); digest ingested bacteria, viruses, & toxins; degrade worn out organelles | lysosomes
🗑
|
||||
| lysosomes are __ in phagocytes | abundant
🗑
|
||||
| lysosomal rupture __ __ autolysis | results in
🗑
|
||||
| self digestion of the cell | autolysis
🗑
|
||||
| system includes nuclear envelope, SER, RER, transport vesicles, Golgi apparatus, lysosomes, & plasma membrane | endomembrane system
🗑
|
||||
| parts of endomembrane system work together to produce/export __ molecules & __ harmful substances | biological; degrade
🗑
|
||||
| membranous sacs containing oxidase & catalase; detoxify harmful/toxic substances; numerous in liver & kidney cells | peroxisome
🗑
|
||||
| peroxisomes __ dangerous free radicals | neutralize
🗑
|
||||
| highly reactive chemicals w/unpaired electrons (i.e. O2-) that can damaged cell components | free radicals
🗑
|
||||
| hollow tubes made of spherical protein tubulin; determine shape of cell & distribution of organelles; radiate from centrosome | microtubules
🗑
|
||||
| microtubules, microfilaments, & intermediate filaments __ __ the cytoskeleton | make up
🗑
|
||||
| strands of protein actin; involved in cell motility, muscle contraction, endocytosis, & exocytosis; 7nm | microfilaments
🗑
|
||||
| tough, protein fibers; resist pulling forces on cell & help form desmosomes; 10nm | intermediate filaments
🗑
|
||||
| paired, consisting of microtubules; located in centrosome near nucleus; form bases of cilia & flagella | centrioles
🗑
|
||||
| generated microtubules for mitotic spindle during cell division | centrosome
🗑
|
||||
| nucleus consists of | nuclear envelope, nucleolus, & chromatin
🗑
|
||||
| gene-containing control center of cell; contains instructions for building nearly all body's proteins | nucleus
🗑
|
||||
| most cells have __ nucleus | one
🗑
|
||||
| referring to nucleus, skeletal muscle cells & osteoclasts are __ | multinucleate
🗑
|
||||
| referring to nucleus, mature RBCs are | anulcleate
🗑
|
||||
| selectively permeable double membrane barrier containing nuclear pores; outer membrane continuous w/RER & studded w/ribosomes | nuclear envelope
🗑
|
||||
| nuclear envelope: through __ __ protein molecules are imported from cytoplasm | nuclear pores;
🗑
|
||||
| nuclear envelope: through nuclear pores RNA __ __ nucleus | exported from
🗑
|
||||
| nuclear envelope encloses jelly-like __ | nucleoplasm
🗑
|
||||
| dark-staining spherical bodies w/in nucleus; site of assembly of 2 types of ribosomal subunits | nucleoli
🗑
|
||||
| in nucleoli, 2 types of ribosomal subunits each consist of __ & __ | rRNA; proteins
🗑
|
||||
| in nucleoli, ribosomal subunits leave through nuclear pores, to form __ ribosomes | functional
🗑
|
||||
| nucleoli are __ in cells making a large amount of proteins | larger
🗑
|
||||
| make up is: 30% DNA, 60% histone proteins, 10% RNA; arranged in units called nucleosomes; 2 varieties consists of extended & condensed | chromatin
🗑
|
||||
| active chromatin that dictates protein synthesis | extended chromatin
🗑
|
||||
| inactive chromatin forms chromosomes when nucleus starts to divide | condensed chromatin
🗑
|
||||
| units within chromatin, made of arrangements of 8 histone proteins & 2 winds of the DNA | nucleosomes
🗑
|
||||
| series of changes cell goes through from time it is formed until it reproduces via interphase | cell cycle
🗑
|
||||
| stage of interphase when metabolic activity & growth, centrioles starts to replicate | G1 (gap 1) phase
🗑
|
||||
| interphase consists of subphases: | G1, S, G2
🗑
|
||||
| stage of interphase when DNA replication takes places | S (synthetic) phase
🗑
|
||||
| stage of interphase when cell prepares for division; enzymes & proteins synthesize | G2 (gap 2) phase
🗑
|
||||
| 1 of 2 major periods in cell life cycle; includes period from cell formation to cell division | interphase
🗑
|
||||
| term interphase reflects idea of resting phase of cell through its meaning of stage __ cell divisions | between
🗑
|
||||
| during interphase cell is carrying out all its routine activities, only "resting" from __ | dividing
🗑
|
||||
| metabolic or growth phase would be __ __ name for interphase | more appropriate
🗑
|
||||
| consists of distinct events: mitosis and cytokinesis | M (mitotic) phase
🗑
|
||||
| process during which chromosomes are redistributed to 2 daughter nuclei; division of nucleus; continuous process w/one stage merging smoothly to next | mitosis
🗑
|
||||
| mitosis __ __ prophase, metaphase, anaphase, and telophase | consists of
🗑
|
||||
| division of cytoplasm that occurs after cell nucleus has divided; division of cytoplasm | cytokinesis
🗑
|
||||
| movement | -kines
🗑
|
||||
| thread | mit-
🗑
|
||||
| -osis | process
🗑
|
||||
| 1st stage mitosis | prophase
🗑
|
||||
| 2nd stage mitosis | metaphase
🗑
|
||||
| 3rd stage mitosis | anaphase
🗑
|
||||
| final phase mitosis | telophase
🗑
|
||||
| mitosis in human cells generally last about __ __, or less, from start to finish | an hour
🗑
|
||||
| in DNA replication, before a cell can __ DNA has to be replicated, which occurs in S phase | divide
🗑
|
||||
| in DNA replication, once DNA is replicated, DNA helices begin __ from nucleosomes | unwinding
🗑
|
||||
| in DNA replication, during the DNA unwinding process, helicases untwists __ __ & __ DNA into two strands | double helix; separates
🗑
|
||||
| in DNA replication, once DNA unwound, each nucleotide strand serves as __ for building new __ strand | template; complementary
🗑
|
||||
| in DNA replication, __ __used to begin DNA synthesis | RNA primers
🗑
|
||||
| in DNA replication, __ __ continues from RNA primer & adds complementary nucleotides to template | DNA polymerase
🗑
|
||||
| in DNA replication, DNA polymerase, only works in __ __ | once direction
🗑
|
||||
| __ __, of DNA polymerase, is synthesized continuously | leading stand
🗑
|
||||
| __ __, of DNA polymerase, is synthesized in segments in opposite direction, then joined w/leading strand | lagging strand
🗑
|
||||
| in DNA replication, 2 __ __ are formed, each having 1 old & new strand | DNA molecules
🗑
|
||||
| in DNA replication, histones are __ from cytoplasm, then __ w/DNA forming 2 chromatin strands | imported; associate
🗑
|
||||
| in DNA replication, chromatin untied by __; condensed to form __ | centromere; chromatids
🗑
|
||||
| in DNA replication, chromatids __ __ until cell enters anaphase | remain attached
🗑
|
||||
| dell division is essential for __ growth & __ repair | body; tissue
🗑
|
||||
| continuously dividing cells e.g. intestinal epithelium, skin; cells that can be stimulated to divide e.g. liver cells; cells that cannot divide e.g. neurons, cardiac muscle & skeletal muscle cells | 3 populations of cells according to their ability to replicate
🗑
|
||||
| in cytokinesis, __cytoplasm is pinched into 2 parts after mitosis ends- two __ cells | cytoplasm; daughter
🗑
|
||||
| chromatin condenses into chromosomes, each appears as sister chromatid held by centromere; nucleoli disappear; centriole pairs separate from each other; microtubules lengthen to form mitotic spindle | early prophase
🗑
|
||||
| nuclear fragments & membrane disappears; centrosomes at opposite poles; microtubules pull each chromosome from both poles | late prophase
🗑
|
||||
| in metaphase, chromosomes cluster at __ of cell w/their __ at equator of spindle | middle; centromeres
🗑
|
||||
| arrangement of chromosomes in plane midway between 2 poles is called | metaphase plate
🗑
|
||||
| in anaphase, centromeres of chromosomes __ | split
🗑
|
||||
| in anaphase, once chromosomes split, each chromosome __ __ a pole by microtubules | pulled toward
🗑
|
||||
| in anaphase, chromosomes look __ | V-shaped
🗑
|
||||
| in telophase, chromosomes have moved to __ __ | opposite poles
🗑
|
||||
| in telophase, chromosomes __ & become thread-like __ | uncoil; chromatin
🗑
|
||||
| in telophase, new nuclear membrane formed from __ __ | rough ER
🗑
|
||||
| in telophase, nucleoli that disappeared in early prophase, __ | reappear
🗑
|
||||
| in telophase, __ spindle appears | mitotic
🗑
|
||||
| in telophase, cytokinesis __ cell division into 2daughter cells | completes
🗑
|
||||
| in protein synthesis, 1 gene carries instruction for creating one __ chain | polypeptide
🗑
|
||||
| in protein synthesis, 1 DNA base triplet codes for one __ __ | amino acid
🗑
|
||||
| in protein synthesis, role of RNA includes: __, __, & __ | mRNA; rRNA; tRNA
🗑
|
||||
| in protein synthesis, carries genetic info from DNA to ribosomes | mRNA
🗑
|
||||
| in protein synthesis, is component of ribosomes | rRNA
🗑
|
||||
| in protein synthesis, loads up w/amino acids & base pairs w/the codons of mRNA at ribosome for synthesis | tRNA
🗑
|
||||
| in protein synthesis, involves transfer of info from DNAs gene base sequence to complimentary base sequence of mRNA | transcription
🗑
|
||||
| in protein synthesis during transcription, this binds to DNA & unwinds 16-18 base pairs at a time | RNA polymerase
🗑
|
||||
| in protein synthesis during transcription, RNA polymerase adds complementary __ __ on DNA template strand; other DNA strands is coding | RNA nucleotides
🗑
|
||||
| in protein synthesis when transcription stops, mRNA strand __ __ DNA | pulls off
🗑
|
||||
| 3 base sequence of mRNA corresponding to a DNA base triplet | codon
🗑
|
||||
| process in which DNA base sequence is translated into amino acid sequence for protein synthesis | translation
🗑
|
||||
| in protein synthesis during translation, once __ is made, it leaves nucleus through the nuclear pores, enters cytoplasm & attaches to __ small subunit | mRNA; ribosome
🗑
|
||||
| in protein synthesis during translation, __ __ initiator tRNA binds to start codon of mRNA (its anticodon base pairs) on ‘P’ site of ribosome | methionine carrying
🗑
|
||||
| in protein synthesis during translation, once methionine carrying initiator tRNA binds to start codon of mRNA on ‘P’ site of ribosome, large __ __ binds to this complex forming a(n) __ __ | ribosomal unit; functional ribosome
🗑
|
||||
| in protein synthesis during translation, 2nd tRNA binds to ‘A’ site on __, matching w/next 3bases on __ | ribosome; mRNA
🗑
|
||||
| in protein synthesis during translation, amino acid carried by 2nd tRNA binds to __, the latter separating from its __ which moves to ‘E ‘ site & exits | methionine; tRNA
🗑
|
||||
| in protein synthesis during translation, polypeptide chain __ till a stop codons is reached __ translation | elongates; ending
🗑
|
||||
| pinocytosis is also called | fluid-phase endocytosis
🗑
|
||||
| receptors for receptor-mediated endocytosis are __ __ __ that bind only certain substances | plasma membrane proteins
🗑
|
||||
| in receptor-mediated endocytosis, receptors & attached molecules are __ in clathrin-coated pit | internalized
🗑
|
||||
| enzymes, insulin & other hormones, low-density lipoproteins (i.e. cholesterol attached to transport protein), & iron are all | substances take up by receptor-mediated endocytosis
🗑
|
||||
| flu viruses, diphtheria, & cholera toxins use receptor-mediated endocytosis to | enter & attack our cells
🗑
|
||||
| tubular or flask-shaped inpocketings of plasma membrane seen in many cell types; capture specific molecules (folic acid, tetanus toxin) from extracellular fluid in coated vesicles & participate in from forms of transcytosis | caveolae
🗑
|
||||
| caveolae are involved in unique kind of receptor-mediated endocytosis called __ | potosis
🗑
|
||||
| caveolae are __ than most vesicles & their cage-like protein coat is __ & compose of caveolin | smaller; thinner
🗑
|
||||
| integral membrane proteins that are principal components of caveola membranes; believed to act as scaffolding for assembly of signaling complexes | caveolin
🗑
|
||||
| caveolae are closely associated w/lipid rafts that are platforms for __ proteins, receptors for hormones and enzymes involved in cell __ | G; regulation
🗑
|
||||
| caveolae vesicles appear to provide sites for cell __ & cross talk btwn __ pathways | signaling; signaling
🗑
|
||||
| 1 of macromolecular protein complexes, composed of 7subunits & present in cytosol, that are assembled to form coat of vesicles that transport proteins btwn cisternae of Golgi complex & btwn Golgi complex & ER | coatomer proteins
🗑
|
||||
| coatomer proteins used in most types of intracellular vesicular trafficking which transport substances btwn organelles | COP1 & COP2
🗑
|
||||
| typically stimulated by cell-surface signal such as binding of hormone to membrane receptor or change in membrane voltage, accounts for hormone secretion, neurotransmitter release, mucus secretion, & in some cases ejection of wastes | process of exocytosis
🗑
|
||||
| in exocytosis, substance to be removed from cell is 1st enclosed in __ __ sac called vesicle | protein-coated membranous
🗑
|
||||
| in exocytosis, once substance to be removed is enclosed in vesicle, vesicle then migrates to plasma membrane, fuses with it, & then __, spilling sac contents, __ of cell | ruptures; out
🗑
|
||||
| exocytosis involves __ process in which transmembrane proteins on vesicles called __ recognize certain plasma membrane proteins, called __ & bind with them | v-SNAREs; t-SNAREs
🗑
|
||||
| binding of v-SNAREs & t-SNAREs causes membranes to __ together & fuse, rearranging lipid monolayers w/out mixing them | corkscrew
🗑
|
||||
| membrane material added by __ is removed by __, the reverse process | exocytosis; endocytosis
🗑
|
||||
| voltage across plasma membrane | membrane potential
🗑
|
||||
| electrical potential energy resulting from separation of oppositely charged particles | voltage
🗑
|
||||
| in cells, oppositely charged particles are __, & barrier that keeps them apart is __ __ | ions; plasma membrane
🗑
|
||||
| because of resting membrane potential all cells are said to be __ | polarized
🗑
|
||||
| a minus side before voltage, of a cell, indicates that the __ of cell is negative compared to its __ | inside; outside
🗑
|
||||
| resting membrane potential voltage, or charge separation, exists __ __ the membrane | only at
🗑
|
||||
| if all the - & + charged in cytoplasm were add up, would find cell interior is __ __ | electrically neutral
🗑
|
||||
| + & - charges in extracellular fluid __ each other out __ | balance; exactly
🗑
|
||||
| resting membrane potential comes about because, diffusion causes ionic imbalances that __ membrane, & active transport processes __ that membrane potential | polarize; maintain
🗑
|
||||
| resting membrane potential is determined mainly by __ __ of K+ & by __ permeability of plasma membrane to K+ & other ions | concentration gradient; differential
🗑
|
||||
| K+ & protein anions __ inside body cells | predominate
🗑
|
||||
| extracellular fluid contains relatively more __, largely balanced by __ | Na+; Cl-
🗑
|
||||
| unstimulated plasma membrane is somewhat permeable to K+ because of __ __, but impermeable to protein __ | leakage channels; anions
🗑
|
||||
| combined difference in concentration & charge; influences distribution & direction of diffusion of ions | electrochemical gradients
🗑
|
||||
| ions diffuse according to __ gradients, thereby recognizing effect of both electrical & __ (chemical) forces | electrochemical; concentration
🗑
|
||||
| although diffusion of K+ across plasma membrane is aided by membrane's greater __ to it & by ion's concentration gradient, its diffusion is resisted somewhat by __ __ on cell exterior | permeability; positive charge
🗑
|
||||
| Na+ is drawn into cell by __ __ gradient, & limiting factor is membrane's relative __ to it | steep electrochemical; impermeability
🗑
|
||||
| upsetting resting membrane potential by __ opening of Na+ & K+ channels in plasma membrane is normal means of __ neurons & muscle cells | transient; activating
🗑
|
||||
| whether cells interact directly/indirectly the glycocalyx is __ __ | always involved
🗑
|
||||
| best understood of participating glycocalyx molecules fall into 2 large families | cell adhesion molecules & plasma membrane receptors
🗑
|
||||
| another group of membrane proteins, which are important in cells that respond to electrical signals | voltage-sensitive channel proteins
🗑
|
||||
| cell surface glycoproteins that mediate intercell adhesion in body; cadherins, integrins | cell adhesion molecules (CAMs)
🗑
|
||||
| sticky glycoproteins (cadherins, integrins) act as molecular "Velcro" that cells use to anchor themselves to molecules in extracellular space & to each other | CAMs
🗑
|
||||
| sticky glycoproteins (cadherins, integrins) act as "arms" that __ cells use to haul themselves past one another | migrating
🗑
|
||||
| sticky glycoproteins (cadherins, integrins) act as SOS signals, sticking out from blood vessel lining that rally __ __ to nearby infected or injured area | protective WBCs
🗑
|
||||
| sticky glycoproteins (cadherins, integrins) act as __ __ that respond to local tension at cell surface by stimulating synthesis or degradation of adhesive membrane junctions | mechanical sensors
🗑
|
||||
| sticky glycoproteins (cadherins, integrins) act as __ of intracellular signals that direct cell migration, proliferation, & specialization | transmitters
🗑
|
||||
| large, diverse group of integral proteins & glycoproteins that serve as binding sites for signaling molecules | membrane receptors definition
🗑
|
||||
| actual coming together & touching of cells, & is means by which cells recognize one another | contact signaling
🗑
|
||||
| contact signaling is particularly important for normal __ & __ | development; immunity
🗑
|
||||
| some bacteria & other infectious agents use contact signaling to identify their "preferred" __ tissues/organs | target
🗑
|
||||
| most plasma membranes receptors are involved in __ signaling | chemical
🗑
|
||||
| different cells respond in different ways to the __ ligand | same
🗑
|
||||
| ligand that stimulates skeletal muscle cells to contract, but inhibits heart muscle | acetylcholine
🗑
|
||||
| target cell's response to chemical signaling depends on __ __ that receptor is linked to, not specific ligand that binds to it | internal machinery
🗑
|
||||
| when ligand binds to membrane receptor, receptor's __ changed, & cell proteins are __ in some way | structure; altered
🗑
|
||||
| example of ligand changing membrane receptor's structure muscle proteins change to __ __ | generate force
🗑
|
||||
| some membrane receptor proteins are __ proteins that function as enzymes | catalytic
🗑
|
||||
| common in muscle/nerve cells; respond to ligands by transiently opening/closing ion gates, which in turn changes excitability of cell | chemically gated channel-linked receptors
🗑
|
||||
| some lipid rafts group together many receptor-mediated elements, thus __ cell signaling | facilitating
🗑
|
||||
| protein that relays signals btwn extracellular 1st messengers, such as hormones or neurotransmitters, & intracellular 2nd messengers, such as cyclic AMP, via an effector enzyme | G protein
🗑
|
||||
| intracellular molecule generated by binding of chemical to plasma membrane receptor; mediates intracellular responses to chemical messenger | 2nd messengers
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| intracellular 2nd messenger that mediates effects of 1st (extracellular) messenger (hormone or neurotransmitter); formed from ATP, by plasma membrane enzyme (adenylate cyclase) | cyclic AMP
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| 2 important 2nd messengers; both typically activate protein kinase enzymes, which transfer phosphate groups from ATP to other proteins | cyclic AMP & ionic calcium
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| when protein kinase is activated by 2nd messenger, it can activate a(n) __ __ of enzymes that bring about desired cellular activity; because single enzyme can catalyze hundred of reactions, this __ __ of such a chain of events is tremendous | whole series; amplification effect
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| key signaling pathway involved in neurotransmission, smell, vision, & hormone action | G protein signaling system
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| one of simplest molecules; 1nitrogen & 1oxygen; environmental pollutant & 1st gas known to act as biological messenger; slips in/out of cells easily; unpaired electrons make highly reactive | NO
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| certain plasma membrane proteins are channel proteins that respond to changes in membrane potential by opening or closing channel | electrical signaling
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| cytoplasm is site where most cellular activities are __ | accomplished
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| cytosol is complex mixture with properties of both a(n) __ & a(n) __ __ | colloid; true solution
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| cytoplasmic organelles are __ __ of cell | metabolic machinery
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| chemical substances that may/may not be present, depending on cell type | inclusions
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| stored nutrients, suck as glycogen granules abundant in liver/muscle cells; lipid droplets common in fat cells; melanin granules seen in certain cells of skin/hair; water-containing vacuoles; & crystals of various types are all | examples of inclusions
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| membrane enabling membranous organelles to maintain internal environment different from that of surrounding cytosol, called __, is crucial to cell functioning | compartmentalization
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| without compartmentalization, thousands of enzymes would be randomly __ & biochemical __ would be chaotic | mixed; activity
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| organelle's membrane often unites it w/rest of interactive intracellular system called __ system | endomembrane
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| organelle membrane's lipid makeup allows it to __ & __ w/other organelles | recognize; interact
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| glycolipid | plasma-membrane lipid possessing a sugar chain that functions in cell recognition
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| phospholipid | most abundant molecule found within lipid bilayer of plasma membrane
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| cholesterol | plasma-membrane lipid that improves rigidity of plasma membrane & increases membrane's impermeability to water
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| protein | component of plasma membrane that can act as doorway for charged particles
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| endocytosis | method by which large particles & macromolecules enter cell by infolding of plasma membrane
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| osmosis | movement of water across a selectively permeable plasma membrane from region of high concentration to region of low concentration
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| exocytosis | mechanism by which substances are moved from cell cytoplasm to outside of cell by fusion of a vesicle w/plasma membrane
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| diffusion | tendency of molecules to move along their concentration gradient from region of high-low concentration
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| transport mechanisms | methods carry molecules, pump molecules, or form channels through which specific molecules pass across plasma membrane
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| phagocytosis | endocytosis of large items, such as bacteria or cellular debris
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| pinocytosis | endocytosis of a tiny quantity of extracellular fluid containing solute molecules
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| receptor-mediated endocytosis | endocytosis that utilizes selective plasma membrane receptor proteins
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| hormones such as insulin, low-density lipoproteins move into cell by | receptor-mediated endocytosis
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| water movement across membrane into cell by | osmosis
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| movement of oxygen, carbon dioxide, and other small uncharged molecules across membrane into cell | diffusion
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| movement of large particles, bacteria, or cellular debris by endocytotic vesicle into cell | phagocytosis
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| molecules moving against the concentration gradient into cell by | active transport mechanisms
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| mitochondrion characteristics | cristae; matrix
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| ribosome characteristics | composed of two subunits; can be "free" in the cytosol or attached to rough ER
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| rough ER characteristics | produces protein transport vesicles
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| Golgi apparatus characteristics | possesses a cis and trans side; composed of cisternae
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| centrioles characteristics | composed of microtubules arranged in nine groups of three
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| microfilaments characteristics | thinnest members of the cytoskeleton are composed of strands of actin protein
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| intermediate filaments characteristics | cytoskeleton members are tough, insoluble protein fibers that possess a high tensile strength
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| microtubules characteristics | hollow tubular members of cytoskeleton composed of spherical protein subunits & can be quickly assembled & disassembled by cell
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| chromatin | strands of DNA and associated histones in the nucleus of a non-dividing cell
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| nuclear envelope, or nuclear membrane | membrane that surrounds the nucleus of a cell
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| nuclear pore | tiny passageway that allows large molecules to freely pass in and out of the nucleus
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| nucleolus | dark-staining body found in the nucleus of a cell that functions in producing ribosomes
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| nucleoplasm | jelly-like fluid found within the nucleus of a cell
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| chromosomes | dark-staining, rod-shaped structures composed of highly coiled chromatin, found in cells undergoing cell division
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| histones | spherical protein molecules around which DNA wraps
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| extended chromatin | fine, uncoiled strands of DNA in the nucleus of a non-dividing cell
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| condensed chromatin | dark-staining regions in the nucleus of a non-dividing cell composed of tightly coiled strands of DNA
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| nucleosome | section of DNA and its eight associated histone proteins
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| G1 | cell is metabolically active, synthesizing proteins, and growing rapidly
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| G2 | cell division enzymes are synthesized, and the centrioles complete replication
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| S | DNA replicates itself
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| metaphase | chromosomes line up along cell equator
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| prophase | chromatin condenses into chromosomes; centrioles move toward opposite poles of the cell
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| anaphase | identical sets of chromosomes moved to opposite sides of cell
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|
||||
| telophase | chromosomes uncoil and revert to chromatin; nuclear membranes form around the sets of chromosomes
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|
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| protein synthesis is function of | ribosomes
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|
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| lipid synthesis is function of | smooth ER
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||||
| intracellular digestion is function of | lysosomes
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|
||||
| organize spindle during mitosis | centrioles
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||||
| support cell & give it shape; involved in cell movements | microtubules
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|
||||
| product produced by mitochondrion | ATP
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|
||||
| product produced by rough ER | transport vesicles
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|
||||
| product produced by Golgi apparatus | lysosomes & secretory vesicles
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|
||||
| product produced by nucleolus | ribosomes
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|
||||
| product produced by centrioles | cilia & flagella (microtubules)
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|
||||
| events occurring in cytokinesis | division of the parent cell cytoplasm into two daughter cells
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|
||||
| events occurring in mitosis | separation of two identical sets of chromosomes to opposite sides of the parent cell
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|
||||
| events occurring in interphase | non-dividing stage involving rapid growth, DNA replication, and preparation for division
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|
||||
| random motion of a substance resulting in movement from area of high to lower concentration | characteristics of diffusion
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|
||||
| passive process utilizing a protein carrier or channel | characteristics of facilitated diffusion
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|
||||
| movement of a substance that utilizes a carrier; energy comes directly from hydrolysis of ATP | characteristics of primary active transport
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|
||||
| movement of a substance that utilizes a carrier, and has a concentration gradient as the source of energy | characteristics of secondary active transport
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|
||||
| carries genetic instructions from nucleus to the site of protein synthesis | function of mRNA
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|
||||
| uses an anticodon to guide its attached amino acid to the complementary codon on the mRNA at the ribosome | function of tRNA
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|
||||
| combines in a complex with proteins to make the large and small subunits of a ribosome | function of rRNA
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|
||||
| can control, or inhibit, certain genes | function of microRNA
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|
||||
| adjacent cells joined by a line of membrane proteins that form an impermeable junction | tight junction
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|
||||
| button-like junctions that use linker proteins to hold adjacent cells together | desmosomes
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|
||||
| adjacent cells held together by connexon proteins that form cylinders allowing ion flow between the cells' cytoplasm | gap junctions
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|
||||
| tiny finger-like projections of the plasma membrane; increase surface area for absorption | microvilli
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|
||||
| motile cellular extensions found in large numbers in some epithelial cells | cilia
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|
||||
| long, cellular projections that are tail-like and aid in propulsion | flagella
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|
||||
| cytoskeleton is an elaborate network of rods running throughout the cytosol, functioning in | supporting cellular structures & generating cell movements
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|
||||
| DNA | nucleic-acid molecules are involved in transcription but not translation in the synthesis of a particular polypeptide
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|
||||
| DNA is copied into mRNA in transcription within the nucleus in the synthesis of a(n) | particular polypeptide
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|
||||
| mRNA start codon, AUG, matches up with a tRNA anticodon | GAC
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|
||||
| definite changes in the __ of the cell membrane can be seen in a cell that is becoming cancerous | glycocalyx
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|
||||
| simple diffusion is best described as substances | moving down a concentration gradient passively
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|
||||
| crenation takes place when a cell is placed in a(n) | hypertonic solution
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|
||||
| type of RNA contains regions that act as a switch to turn protein synthesis on & off for the protein it codes for | Riboswitches
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|
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