Question | Answer |
Smooth ER | Synthesized lipids and steroids |
Centrioles | Functions in cell reproduction |
Rough ER | Transports synthesized protein |
Cytoplasm | Living material of the cell |
Cell membrane functions | Cell boundary, maintain integrity, protein molecules in plasma membrane perform various functions (identify, receptor, transport). Chemical attraction holds together from phospholipids |
Mitochondria | Powerhouses, ATP is synthesized here |
Golgi apparatus | Packages ER (endoplasmic reticulum) substances (protein). Synthesizes carbohydrates, combine protein and packages the product as globules of glycoprotein |
Nucleus | Plays role in growth and heredity, control center of the cell |
Lysosomes | Digestive system, breaks down defective cell parts and ingests particles |
Ribosomes | Protein factory, protein synthesis, found in cytoplasm as free floating or connected to ER. non membranous, made of two into interlocking pieces a large and small subunit |
Nucleolus | part of the nucleus, Ribosome formation |
Carbohydrates | Attach to the surface of cells, forming glycoprotein molecules that aid in cell type identification. |
Proteins | In the phospholipids bilayer, control what moves through the membrane. Many membrane proteins have openings that allow water-soluble molecules to pass through. Specific kinds of transport proteins allow only certain kinds of molecules to pass through. |
Phospholipids | Form the fluid framework for plasma membrane. Have a hydrophobic and a hydrophilic region. Add to water, they self-assemble into aggregates so the phosphate heads contact water and the hydrophobic hydrocarbon tails are restricted to water-free areas. |
Plasma Membrane | It is a fluid mosaic composed of phospholipids, cholesterol, carbohydrates, and protein and is structured so that only selected substances can pass through this unique membrane. |
Cytoskeleton | Internal supporting framework, is made up of rigid, rodlike pieces that provide support and allow movement and mechanisms that can move the cell or its parts. Forms cell extensions (micro villa, cilia, flagella) |
Cell fibers | Support the ER, mitochondria, & ribosomes.
Micro filament
Intermediate filaments
Microtubules |
Centrosomes | A region of the cytoplasm near the nucleus that coordinates the building and breaking of microtubules. Boundaries are indistinct because it lacks a membranous wall. Identified by locating centrioles. The centrioles are active during cell division. |
Cell extensions | Cytoskeleton forms projections that extend the plasma membrane outward to form tiny, fingerlike processes. They are present in only certain types of cells. The three types of processes are microvilli, cilia, and flagella. |
Cilia | Nonmembranous, hairlike cell extensions that serve to move substances over the cell surface |
Flagella | non-membranous, single cell extension that serves to propel cells with whip like action (only found in sperm) |
Main cell structures | Plasma membrane
Cytoplasm
Nucleus |
Cytosol | intracellular fluid, the watery fluid inside the cytoplasm. |
Prime regulator of nucleus functions | DNA |
Nucleus | spherical body in center of cell; enclosed by an envelope with pores |
Structure and components of Nucleus | Consists of nuclear envelope (composed of 2 membranes with the same molecular structure as plasma membrane) surrounding nucleoplasm; nuclear envelope has holes called nuclear pores .Contains DNA ,determines structure & function of cells & heredity |
Cell Structures that contain DNA | Nucleus |
Composition of cell membrane | Variety of membranes (plasma membrane, Membranous organelles—sacs and canals)
Chemical attractions are the forces that hold membranes together
Primary structure of a cell membrane is a double layer of phospholipid molecule |
Cell membrane | separates the interior of all cells from the outside environment |
Phagocytosis | ingestion and digestion of particles by a cell |
Elements that control movement of materials through a cell membrane | Membrane proteins embedded in the phospholipid bilayer.
Some have carbohydrates attached, forming glycoproteins - identification markers
Some are receptors that react to specific chemicals, permitting a process called signal transduction |
Three types of cell connections | Tight junction
Gap junction
Desmosomes |
Tight junction | Joined by “collars” of tightly fused material
Molecules cannot permeate the cracks
Occur in the lining of the intestines and other parts of the body, where it is important to control what gets through a sheet of cells |
Gap junctions | membrane channels of adjacent plasma membranes adhere to each other; have two effects:
Form gaps or “tunnels” that join the cytoplasm of two cells
Fuse two plasma membranes into a single structure
Occur in heart muscle cells. |
Desmosomes | Fibers on the outer surface interlock with each other; anchored internally by intermediate filaments of the cytoskeleton
Spot: connecting adjacent membranes, like “spot welds” at various points
Belt: encircle the entire cell like a collar |
Osmosis | Diffusion of water through a selectively permeable membrane, which limits the diffusion of at least some of the solute particles |
Diffusion | passive process, molecules spread or move down a concentration gradient. As molecules diffuse, a state of equilibrium will occur |
Largest human cell | Ovum |
Membranous organelles | plasma membrane
endoplasmic reticulum(ER)
golgi apparatus
vesicles
lysosomes
proteasomes
peroxisomes
mitochondria
nucleus |
Non-membranous organelles | ribosomes
proteasomes
cytoskeleton
centrosome
microvilli
cilia and flagella
nucleolus |
Hydrophobic arrangement of cell membrane | water fearing, tail that is lipid soluble
most are, therefore water or water-soluble molecules do not pass through easily |
Hydrophilic arrangement of cell membrane | water loving, head that is water soluble |
Major substances that can pass through the cell membrane | Oxygen
Carbon Dioxide |
Substances that can not pass through the cell membrane | Electrically charged substances can not/must pass through pores- sodium chloride
Water or water-soluble molecules
Substances larger than the pores
Bacteria
cancer cell
blood donations with out similar cell markers |
Carrier- mediated transport | Passive transport
Carriers attract and bind to solute, change shape, and release the solute out the other side of the carrier
Reversible, depending on the direction of the concentration gradient |
Enzyme reactions | catalyze a chemical reaction in both directions
Chemical catalysis that reduce the activation energy needed for reaction
Regulate cell metabolism
Oxidation- Reduction
Hydrolyzing
Phosphorylating
Carboxylases/ Decarboxylases
Mutases/ Isomerases
H |
Mature human cells | M phase: reproduce by first distributing two identical set of DNA (mitosis)
Cytokinesis: two daughter cells |
Immature human cells | G1 and G2: grow to maturity by synthesizing new molecules and organelles
S phase: replication of an extra set of DNA in anticipation of reproductio |
Cellular respiration | Pathway in which glucose is broken down to yield its stored energy. Example of cell catabolism
Three pathways:
Glycolysis
Citric acid cycle
Electron transport system (ETS) |
Phases of Mitosis | Interpahse
Prophase
Metaphase
Anaphase
Telophase |
Mitosis | process of organizing and disturbing nuclear DNA during cell division |
Meiosis | specialized cell division of sex cells. reduction of chromosomes from diploid to the haploid number take place |
Active transport | requires the expenditure of metabolic energy by the cell
Transport by pumps
Transport by vesicles
Endocytosis
Exocytosis |
Transport by pumps | Pumps are membrane transporters that move a substance against its concentration gradient—the opposite of diffusion
Examples: calcium pumps and sodium-potassium pumps |
Transport by vesicles | allows substances to enter or leave the interior of a cell without actually moving through its plasma membrane |
Endocytosis | the plasma membrane “traps” some extracellular material and brings it into the cell in a vesicle
Two basic types
Phagocytosis—“condition of cell-eating”
Pinocytosis—“condition of cell-drinking” |
Exocytosis | large molecules (proteins) can leave the cell even though they are too large to move out through the plasma membrane
enclosed in vesicles then pulled by the cytoskeleton to the plasma membrane
way for new material to be added to the plasma membrane |
Passive transport | Do not require any energy expenditure of the cell membrane, move substance down their concentration gradient
Simple diffusion
Osmosis
Facilitated diffusion
channel-mediated
carrier-mediated |
Hypotonic solution | Low pressure, expand or bloat
solution that has a lower solute concentration than the cell, the cells draw water attempting to equalize- trying to create isotonic/ homeostatic environment (causes to swell and rupture) |
Hypertonic solution | High pressure, shrivel or compress
solution contains a level of salt that is higher than o.9% . they draw water from surrounding cells in an attempt to create an isotonic/ homeostatic environment (causes cells to shrink) |
Transcription | process in which DNA molecule is used as a template to form mRNA
Messenger RNA receives the genetic information from the DNA during the first stage of protein synthesis
mRNA forms along a segment of one strand of DNA |
Translation | mRNA code delivered to ribosome, then is used by ribosomes in the synthesis of a protein
Second stage of the transfer of info from DNA
Can be inhibited by RNA interference (RNAi)—protecting the cell against viral infection |
Catabolism | energy source, breaks large molecules into smaller ones; releasing energy
Example- Cellular respiration |
Anabolism | building block for making complex chemical compounds; consumes energy
Protein Synthesis is a central anabolic pathway in cells
Example: DNA (call shots)
Example: RNA ( carries on forward) |