Question | Answer |
light microscope (lm) | visible light is passed through the specimen and then through glass lenses. the lenses refract (bend) the light in such a way that the image of the specimen is magnified as it is projected into the eye or into a camera. |
organelles | the membrane-enclosed structures within eukaryotic cells. |
electron microscope | focuses a beam of electrons through a specimen or onto its surface. |
transmission electron microscope (TEM) | used to study the internal structure of cells. This microscope aims an electron beam through a very thin section of specimen. |
scanning electron microscope (SEM) | useful for detailed study of the topography of a specimen. Controlled by electromagnetic lenses, an electron beam scans the surface of the sample, usually coated in a thin coat of gold. |
cell fractionation | a technique for studying cell structure & function. The disruption of a cell and separation of its parts by centrifugation at successively higher speeds. |
cytosol | a semifluid jellylike substance found in all cells in which subcellular components are suspended. |
nucleus | this organelle is found in a eukaryotic cell and carries most of the DNA. this organelle is bounded by a double membrane. |
Nucleoid | a non-membrane enclosed region in a prokaryotic cell where its chromosome is located. |
cytoplasm | the contents of the cell enclosed by the plasma membrane; in eukaryotes the portion exclusive of the nucleus. |
plasma membrane | the membrane at the boundary of every cell that acts as a selective barrier, regulating the cells chemical composition. |
flagellum | motility structure present in some animal cells, composed of a cluster of microtubules w/in an extension of the plasma membrane. |
centrosome | region where the cell's microtubules are initiated; contains a pair of centrioles. |
cytoskeleton | reinforces cell's shape; functions in cell movement; components are made of protein. Includes: microfilaments, intermediate filaments, microtubules. |
microvilli | projections that increase the cell's surface |
peroxisome | organelle wivarious specialized metabolic functions; produces hydrogen peroxide as a by product, then converts it to water. |
mitochondrion | the sites of cellular respiration, the metabolic process that uses oxygen to generate ATP by extracting sugars, fats, and other fuels. |
lysosome | digestive organelle where macromolecules are hydrolyzed. |
Golgi apparatus | organelle active in synthesis, modification, sorting, & secretion of cell products. |
ribosomes | complexes that make proteins; free in cytosol or bound to rough ER or nuclear envelope. |
plasma membrane | membrane enclosing the cell |
chromatin | material consisting of DNA & proteins; visible in a dividing cell as individual condensed chromosomes. |
nucleolus | nonmembranous structure involved in production of ribosomes; a nucleus has one or more nucleoli. |
nuclear envelope | double membrane enclosing the nucleus; perforated by pores; continuous with ER. |
Endoplasmic reticulum | network of membranous sacs and tubes; active in membrane synthesis and other synthetic and metabolic processes; has rough (studded with ribosomes) and smooth regions. |
in animal cells, but not in plant cells: | lysomes, centrosome, with centrioles flagella |
in plant cells but not in animal cells: | chloroplasts, central vacuole, cell wall, plasmodesmata |
cell wall | outer layer that maintains cells shape and protects cell from mechanical damage; made of cellulose, other polysaccharides and protein (found in plant cells). |
plasmodesmata | channels through cell walls that connect the cytoplasms of adjacent cells (found in plant cells) |
chloroplast | photosynthetic organelle; converts energy of sunlight to chemical energy stored in sugar molecules (found in plant cells) |
central vacuole | prominent organelle in older plant cells; functions include storage, breakdown of waste products, hydrolysis of macromolecules, enlargement of vacuole is a major mechanism of plant growth. |
where are the eukaryotic cell's genetic instructions housed? | in the nucleus and carried out by the ribosomes. |
which cells have internal membranes that compartmentalize their functions? | eukaryotic cells |
which system regulates protein traffic and performs metabolic functions in the cell? | endomembrane system |
glycoproteins | proteins that have carbohydrates covalently bonded to them. |
phagocytosis | a type of endocytosis in which large particulate substances or small organisms are taken up by a cell. |
autophagy | lysosomes use their hydrolytic enzymes to recycle the cell's own organic material. |
endosymbiont theory | this theory states that an early ancestor of eukaryotic cells engulfed an oxygen-using nonphotosynthetic prokaryotic cell. the evolutionary origins of mitochondria and chloroplasts. |
Nuclear lamina | A net like array of protein filaments that maintains the shape of the nucleus by mechanically supporting the nuclear envelope. |
Chromosomes | A cellular structure consisting of one DNA molecule and associated protein molecules. |
Ribosomes | Complexes made of ribosomal RNA and protein. |
Free ribosomes | Complexes suspended in cytosol |
Bound ribosomes | Complexes attached to the outside of the endoplasmic reticulum or nuclear envelope. |
vesicles | Sacs made of membrane |
2 distinct regions of ER | Smooth ER and rough ER |
Smooth ER | a region of ER that lacks ribosomes |
Rough ER | A region of ER that is studded with ribosomes |
microtubules | hollow tubes; consists of 13 columns of tubulin molecules. functions in the maintenance of a cells shape, cell motility, chromosome movements in cell division, & organelle movements |
microfilaments | 2 intertwined strands of actin, each a polymer of actin subunits. Functions in the maintenance of the cells shape, changes in cell shape, muscle contraction, cytoplasmic streaming in plant, cell motility, & division of animal cells. |
intermediate filaments | fibrous proteins that supercoiled into thicker cables, functions in the maintenance of a cells shape, anchorage of nucleus and certain other organelles, formation of nuclear lamina. |
cristae | an in-folding of the inner membrane of mitochondrion. the inner membrane houses electron transport chains and molecules of the enzyme catalyzing the synthesis of ATP. |
mitochondria are responsible for | chemical energy conversion |
mitochondria and chloroplasts change | energy from one form to another. |
vacuoles are diverse | maintenance compartments |
the golgi apparatus is called | the shipping and receiving center |
the _________ _________ regulates protein traffic and performs metabolic functions in the cell. | endomembrane system |
The ________ ____________ genetic instructions are housed in the nucleus and carried out by the ribosomes. | eukaryotic cell"s |
_____ ______ have internal membranes that compartmentalize their functions. | eukaryotic cells |
thylakoid | a flattened, membranous sac inside a chloroplast. thylakoids often exist in stacks called grana that are interconnected; their membranes contain molecular "machinery" used to convert light energy to chemical energy. |
stroma | the fluid outside of the thylakoid that contains the chloroplast DNA and ribosomes as well as many enzymes. |
palstids | One of a family of closely related organelles that includes chloroplasts, chromoplasts, and amyloplasts. plastids are found in the cells of photosynthetic eukaryotes. |
motor proteins | a protein that interacts with cytoskeleton elements and other cell components, producing movement of the whole cell or parts of the cell. |
_____ _______ generally requires the interaction of the cytoskeleton with motor proteins. | cell motility |
centrioles | found in pairs in the centrosome; each composed of 9 sets of triplet microtubules arranged in a ring. |
cilia | a short appendage containing microtubules in eukaryotic cells. |
a ____ ______ is specialized for locomotion or moving fluid past the cell. the 9 + 2 arrangement. | motile cilium |
a _____ ______ is usually nonmotile and plays a sensory and signaling role. it lacks the 2 inner microtubules; the 9 + 0 arrangement. | Primary cilium |
actin | a globular protein |
basal body | a eukaryotic cell structure consisting of 9 + 0 arrangement of microtubule triplets. |
dynein | in cilia and flagella, a large motor protein extending form one microtubule doublet to the adjacent doublet. ATP hydrolysis drives changes in the dynein shape that lead to bending of cilia and flagella. |
The _____ is a network of fibers that organizes structures and activities in the cell. | cytoskeleton |
the 2 major roles of cytoskeleton | support and motility |
the role of peroxisomes | Oxidation |
Extracellular components and connections between cells help coordinate ______ _______. | cellular activities |
myosin | a type of motor protein that associates into filaments that interact with actin filaments , causing cell contraction. |
primary cell wall | the thin and flexible first wall secreted by a plant. |
middle lamella | a thin layer rich in sticky polysaccharides called pectins. |
secondary cell wall | the wall, added by other cells, between the primary wall and the plasma membrane. this wall is often deposited in several laminated layers so it has a strong & durable matrix that affords the cell protection and support. |
extracellular matrix | the meshwork surrounding animal cells, consisting of glycoproteins, polysaccharides, and proteoglycans synthesized and secreted by the cells. |
proteoglycan | a large molecule consisting of a small core protein with many carbohydrate chains attached, found in extracellular matrix of animal cells. |
collegan | a glycoprotein in the extracellular matrix of animal cells that forms strong fibers, found extensively in in connective tissue and bone, the most abundant protein in the animal kingdom. |
fibronectin | an extracellular glycoprotein secreted by animal cells that helps them attach to the extracellular matrix. |
integrin | in animal cells, a transmembrane receptor protein with 2 subunits that interconnects the extracellular matrix and the cytoskeleton. |
in animal cells, the 3 main types of cell junctions: | tight, desmosomes, & gap |
tight junction | in animal cells, the plasma membranes of neighboring cells are very tightly pressed against each other, bound together by specific proteins. |
desmosomes | also called anchoring junctions, in animal cells, function like rivets, fastening cells together into strong sheets. |
gap junctions | in animal cells, provide cytoplasmic channels from one cell to an adjacent cell. |
_____ _____ lack nuclei and other membrane-enclosed organelles. | prokaryotic cells |
organelles found in both plant and animal cells | nucleus, Endoplasmic reticulum, Golgi apparatus, and mitochondria. |
which structure is not part of the endomembrane system? nuclear envelope, chloroplast, Golgi apparatus, plasma membrane, ER | chloroplast |
which structure is common to plant and animal cells? Chloroplast, wall made of cellulose, central vacuole, mitochondrion, centriole | mitochondrion |
which of the following is present in a prokaryotic ell? mitochondrion, ribosome, nuclear envelope, chloroplast, ER | ribosome |
which structure-function pair is mismatched?
nucleolus; production of ribosomal subunits, lysosome; intracellular digestion, ribosome; protein synthesis, microtubule; muscle contraction | microtubule; muscle contraction |
cyaninde binds to at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the? Mitochondria, ribosomes, peroxisomes, lysosomes, ER | mitochondria |
what is the most likely pathway to be taken by a newly synthesized protein that will be secreted by a cell? Golgi>ER>lysosome, nucleus>ER>Golgi, ER>Golgi>vesicles that fuse with plasma membrane, ER>lysosomes>vesicles that fuse with plasma membrane | ER>Golgi>vesicles that fuse with plasma membrane |
which cell is best for studying lysosomes?
muscle cell, nerve cell, phagocytic white blood cell, leaf of a plant cell, bacterial cell | phagocytic white blood cell |