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Chapter 6: A Tour of the Cell

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91938026Light MicroscopesAn optical instrument with lenses that refract visible light to magnify images of specimens
91938027OrganellesOne of several formed bodies with specialized functions, suspended in the cytoplasm of eukaryotic cells
91938028Electron MicroscopeA 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 is
91938029Scanning Electron MicroscopeUsed to study the fine details of cell surfaces.
91938030Transmission Electron MicroscopeUsed to study the internal structure of thin sections of cells
91938031Cell FractionationThe disruption of a cell and separation of its organelles by centrifugation
91938032UltracentrifugesAn intense centrifuge that can spin at up to 1,000,000 g's
91938033CytosolThe semifluid portion of the cytoplasm
91938034Prokaryotic CellA type of cell lackinng a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with prokaryotic cells are called prokaryotes
91938035NucleoidA dense region of DNA in a prokaryotic cell
91938036Eukaryotic CellA type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles. Organisms with eukaryotic cells are called eukaryotes.
91938037CytoplasmThe entire contents of the cell, exclusive of the nucleus, and bounded by the plasma membrane
91938038Plasma MembraneThe membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition
91938039NucleusThe chromosome containing organelle of a eukaryotic cell
91938040Nuclear EnvelopeThe membrane in eukaryotes that encloses the nucleus, separating it from the cytoplasm
91938041Nuclear LaminaA netlike array of protein filaments that maintains the shape of the nucleus
91938042ChromosomesA threadlike, gene-carrying stucture found in the nucleus. Each chromosome consists of one very long DNA molecule and associated proteins
91938043ChromatinThe 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
91938044NucleolusA specialized structure in the nucleus, formed from various chromosomes and active in the synthesis of ribosomes
91938045RiosomesA cell organelle constructed in the nucleolus and functioning at the site of protein synthesis in the cytoplasm; consists of rRNA and protein molecules, which make up two subunits
91938046Endomembrane SystemThe collection of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles
91938047VesiclesA sac made of membrane inside of cells
91938048Endoplasmic ReticulumAn extensive membranous network in eukaryotic cells, continuous with the outer nuclear membrane and composed of ribosome-studded and ribosome-free regions
91938049Smooth ERThat portion of the endoplasmic reticulum that is free of ribosomes
91938050Rough ERThat portion of the endoplasmic reticulum studded with ribosomes
91938051GlycoproteinsA protein covalently attached to a carbohydrate
91938052Transport VesiclesA tiny membranous sac in a cell's cytoplasm carrying molecules produced by the cell
91938053Golgi ApparatusAn organelle in eukaryotic cells consisting of stacks of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum
91938054PhagocytosisA type of endocytosis involving large, particulate substances, accomplished mainly by macrophages, neutrophils, and dendritic cells
91938055LysosomesA membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of eukaryotic cells
91938056Food VacuolesA membranous sac formed by phagocytosis
91938057Contractile VacuolesAmembranous sac that helps move excess water out of certain cells
91938058Central VacuoleA membranous sac in a mature plant cell with deverse roles in reproduction, growth, and development
91938059TonoplastA 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
91938060MitochondriaAn organelle in eukaryotic cells that serves as the site of cellular respiration
91938061ChloroplastsAn 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
91938062PeroxisomeA microbody containing enzymes that transfer hydrogen from various substrates to oxygen, producing that then degrading hydrogen peroxide
91938063CristaeAn infolding of the inner membrane of a mitochondrion that houses the electron transport chain and the enzyme catalyzing the synthesis of ATP
91938064Mitochondrial MatrixThe compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the krebs cycle
91938065PlastidsOne of a family of closely related plant organelles that includes chloroplasts, chromoplasts, and amyloplasts
91938066ThylakoidsA flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy
91938067GranumA stacked portion of the thylakoid membrane in the chloroplast. Grana function in the light reactions of photosynthesis
91938068StromaThe fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water
91938069CytoskeletonA network of microtubules, microfilaments, and intermediate filaments that branch throughout the cytoplasm and serve a variety of mechanical and transport functions
91938070MicrotubulesA hollow rod of tubulin protein in the cytoplasm of all eukaryotic cells and in cilia, flagella, and the cytoskeleton
91938071MicrofilamentsA 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
91938072Intermediate FilamentsA component of the cytoskeleton that includes all filaments intermediate in size between microtubules and microfilaments
91938073CentrosomeMaterial present in the cytoplasm of all eukaryotic cells, important during cell division; the microtubule organizing center
91938074CentriolesA 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
91938075FlagellaA long cellular appendage specialized for locomotion. The flagella of prokaryotes and eukaryoted differ in both structure and function
91938076CiliaA 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
91938077Basal BodyA eukaryotic cell organelle consisting of a 9+0 arrangement of microtubule triplets; may organize the microtubule assembly of a cilium of flagellum; structurally identical to a centriole
91938078DyneinA large contractile protein forming the side-arms of microtubule doublets in cilia and flagella
91938079ActinA globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other contractile elements in cells
91938080PseudopodiaA cellular extension of amoeboid cells used in moving and feeding
91938081Cytoplasmic StreamingA circular flow of cytoplasm, involving myosin and actin felaments, that speeds the distribution of materials within cells
91938082Primary Cell WallA relatively thin and flexible layer first secreted by a young plant cell
91938083Middle LamellaA thin layer of adhesive extracellular material, primarily pectins, found between the primary walls of adjacent yound plant cells
91938084Secondary Cell WallA strong and durable matrix often deposited in several laminated layers for plant cell protection and support
91938085Extracellular MatrixThe substance in which animal tissue cells are embedded, consisting of protein and polysaccharides
91938086CollagenA 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
91938087ProteoglycansA glycoprotein in the extracellular matrix of animal cells, rich in carbohydrate
91938088FibronectinA glycoprotein that helps cells attach to the extracellular matrix
91938089IntegrinsA receptor protein built into the plasma membrane that interconnects the extracellular matrix and the cytoskeleton
91938090PlasmodesmataAn open channel in the cell wall of a plant through which strands of cytosol connect from an adjacent cell
91938091Tight JunctionsA type of intercellular junction in animal cells that prevents the leakage of material between cells
91938092DesmosomesA type of intercellular junction in animal cells that funcitons as an anchor
91938093Gap JunctionsA type of intercellular junction in animal cells that allows the passage of material or current between cells

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