Ap Bio Chapter 6

207163576	actin	A globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other contractile elements in cells.
207163577	aminopeptidase	An enzyme found within the small intestine that splits off one amino acid at a time, beginning at the opposite end of the polypeptide containing a free carboxyl group.
207163578	basal body	A eukaryotic cell organelle consisting of a 9 + 0 arrangement of microtubule triplets; may organize the microtubule assembly of a cilium or flagellum; structurally identical to a centriole.
207163579	cell fractionation	The disruption of a cell and separation of its organelles by centrifugation.
207163580	cell wall	A protective layer external to the plasma membrane in plant cells, bacteria, fungi, and some protists. In plant cells, the wall is formed of cellulose fibers embedded in a polysaccharide-protein matrix. The primary cell wall is thin and flexible, whereas the secondary cell wall is stronger and more rigid and is the primary constituent of wood.
207163581	central vacuole	A membranous sac in a mature plant cell with diverse roles in reproduction, growth, and development.
207163582	centriole	A structure in an animal cell composed of cylinders of microtubule triplets arranged in a 9 + 0 pattern. An animal cell usually has a pair of centrioles involved in cell division.
207163583	centrosome	Material present in the cytoplasm of all eukaryotic cells, important during cell division; the microtubule-organizing center.
207163584	chloroplast	An organelle found only in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water.
207163585	chromatin	The complex of DNA and proteins that makes up a eukaryotic chromosome. When the cell is not dividing, chromatin exists as a mass of very long, thin fibers that are not visible with a light microscope.
207163586	chromosome	A threadlike, gene-carrying structure found in the nucleus. Each chromosome consists of one very long DNA molecule and associated proteins. See chromatin.
207163587	cilium	A short cellular appendage specialized for locomotion, formed from a core of nine outer doublet microtubules and two inner single microtubules ensheathed in an extension of plasma membrane.
207163588	collagen	A glycoprotein in the extracellular matrix of animal cells that forms strong fibers, found extensively in connective tissue and bone; the most abundant protein in the animal kingdom.
207163589	contractile vacuole	A membranous sac that helps move excess water out of the cell.
207163590	crista	(plural, cristae) An infolding of the inner membrane of a mitochondrion that houses the electron transport chain and the enzyme catalyzing the synthesis of ATP.
207163591	cytoplasm	The entire contents of the cell, exclusive of the nucleus, and bounded by the plasma membrane.
207163592	cytoplasmic streaming	A circular flow of cytoplasm, involving myosin and actin filaments, that speeds the distribution of materials within cells.
207163593	cytoskeleton	A network of microtubules, microfilaments, and intermediate filaments that branch throughout the cytoplasm and serve a variety of mechanical and transport functions.
207163594	cytosol	The semifluid portion of the cytoplasm.
207163595	desmosome	A type of intercellular junction in animal cells that functions as an anchor.
207163596	dynein	A large contractile protein forming the side-arms of microtubule doublets in cilia and flagella.
207163597	electron microscope (EM)	A microscope that focuses an electron beam through a specimen, resulting in resolving power a thousandfold greater than that of a light microscope. A transmission electron microscope (TEM) is used to study the internal structure of thin sections of cells. A scanning electron microscope (SEM) is used to study the fine details of cell surfaces.
207163598	endomembrane system	The collection of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.
207163599	eukaryotic cell	A type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles, present in protists, plants, fungi, and animals; also called eukaryote.
207163600	extracellular matrix (ECM)	The substance in which animal tissue cells are embedded, consisting of protein and polysaccharides.
207163601	fibronectin	A glycoprotein that helps cells attach to the extracellular matrix.
207163602	flagellum	(plural, flagella) A long cellular appendage specialized for locomotion. The flagella of prokaryotes and eukaryotes differ in both structure and function.
207163603	food vacuole	A membranous sac formed by phagocytosis.
207163604	gap junction	A type of intercellular junction in animal cells that allows the passage of material or current between cells.
207163605	glycoprotein	A protein covalently attached to a carbohydrate.
207163606	Golgi apparatus	An organelle in eukaryotic cells consisting of stacks of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum.
207163607	granum	(plural, grana) A stacked portion of the thylakoid membrane in the chloroplast. Grana function in the light reactions of photosynthesis.
207163608	integrin	A receptor protein built into the plasma membrane that interconnects the extracellular matrix and the cytoskeleton.
207163609	intermediate filament	A component of the cytoskeleton that includes all filaments intermediate in size between microtubules and microfilaments.
207163610	light microscope (LM)	An optical instrument with lenses that refract (bend) visible light to magnify images of specimens.
207163611	lysosome	A membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of eukaryotic cells.
207163612	microfilament	A solid rod of actin protein in the cytoplasm of almost all eukaryotic cells, making up part of the cytoskeleton and acting alone or with myosin to cause cell contraction.
207163613	microtubule	A hollow rod of tubulin protein in the cytoplasm of all eukaryotic cells and in cilia, flagella, and the cytoskeleton.
207163614	middle lamella	A thin layer of adhesive extracellular material, primarily pectins, found between the primary walls of adjacent young plant cells.
207163615	mitochondrial matrix	The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the Krebs cycle.
207163616	mitochondrion	(plural, mitochondria) An organelle in eukaryotic cells that serves as the site of cellular respiration.
207163617	myosin	A type of protein filament that interacts with actin filaments to cause cell contraction.
207163618	nuclear envelope	The membrane in eukaryotes that encloses the nucleus, separating it from the cytoplasm.
207163619	nuclear lamina	A netlike array of protein filaments that maintains the shape of the nucleus.
207163620	nucleoid	A dense region of DNA in a prokaryotic cell.
207163621	nucleolus	(plural, nucleoli) A specialized structure in the nucleus, formed from various chromosomes and active in the synthesis of ribosomes.
207163622	nucleus	(1) An atom's central core, containing protons and neutrons. (2) The chromosome-containing organelle of a eukaryotic cell. (3) A cluster of neurons.
207163623	organelle	One of several formed bodies with specialized functions, suspended in the cytoplasm of eukaryotic cells.
207163624	peroxisome	A microbody containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide.
207163625	phagocytosis	A type of endocytosis involving large, particulate substances, accomplished mainly by macrophages, neutrophils, and dendritic cells.
207163626	plasma membrane	The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition.
207163627	plasmodesma	(plural, plasmodesmata) An open channel in the cell wall of plant through which strands of cytosol connect from an adjacent cell.
207163628	plastid	One of a family of closely related plant organelles that includes chloroplasts, chromoplasts, and amyloplasts (leucoplasts).
207163629	primary cell wall	A relatively thin and flexible layer first secreted by a young plant cell.
207163630	prokaryotic cell	A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea.
207163631	proteoglycan	A glycoprotein in the extracellular matrix of animal cells, rich in carbohydrate.
207163632	pseudopodium	(plural, pseudopodia) A cellular extension of amoeboid cells used in moving and feeding.
207163633	ribosome	A cell organelle constructed in the nucleolus and functioning as the site of protein synthesis in the cytoplasm; consists of rRNA and protein molecules, which make up two subunits.
207163634	rough ER	That portion of the endoplasmic reticulum studded with ribosomes.
207163635	scanning electron microscope (SEM)	A microscope that uses an electron beam to scan the surface of a sample to study details of its topography.
207163636	secondary cell wall	A strong and durable matrix often deposited in several laminated layers for plant cell protection and support.
207163637	smooth ER	That portion of the endoplasmic reticulum that is free of ribosomes.
207163638	stroma	The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water.
207163639	thylakoid	A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.
207163640	tight junction	A type of intercellular junction in animal cells that prevents the leakage of material between cells.
207163641	tonoplast	A membrane that encloses the central vacuole in a plant cell, separating the cytosol from the vacuolar contents, called cell sap; also known as the vacuolar membrane.
207163642	transmission electron microscope (TEM)	A microscope that passes an electron beam through very thin sections; primarily used to study the internal ultrastructure of cells.
207163643	transport vesicle	A tiny membranous sac in a cell's cytoplasm carrying molecules produced by the cell.
207163644	vesicle	A sac made of membrane inside of cells.