| 246841854 | light microscope (LM) | a microscope where visible light is passed through the specimen and then through glass lenses | |
| 246841855 | organelles | membrane-enclosed structures within eukaryotic cells | |
| 246841856 | electron microscope (EM) | a microscope that focuses a beam of electrons through the specimen or onto its surface | |
| 246841857 | scanning electron microscope (SEM) | a microscope used for detailed study of the topography of a specimen | |
| 246841858 | transmission electron microscope (TEM) | a microscope used to study the internal structure of cells | |
| 246841859 | cell fractionation | a useful technique for studying cell structure and function which takes cells apart and separates major organelles and other subcellular structures from one another | |
| 246841860 | cytosol | a semifluid, jellylike substance in which subcelluar components are suspended | |
| 246841861 | eukaryotic cell | an animal, plant, protist, or fungi cell in which most of the DNA is in an organelle called the nucleus | |
| 246841862 | prokaryotic cell | a bacteria cell in which the DNA is concentrated in a region that is not membrane enclosed | |
| 246841863 | nucleoid | a dense region of DNA in a prokaryotic cell | |
| 246841864 | cytoplasm | the interior of either type of cell | |
| 246841865 | plasma membrane | the boundary of every cell, which functions as a selective barrier that allows passage of enough oxygen, nutrients, and wastes to service the entire cell | |
| 246841866 | nucleus | contains most of the genes in the eukaryotic cell | |
| 246841867 | nuclear envelope | encloses the nucleus, separating its contents from the cytoplasm | |
| 246841868 | nuclear lamina | a netlike array of protein filaments that maintains the shape of the nucleus by mechanically supporting the nuclear envelope | |
| 246841869 | chromatin | the complex of DNA and proteins making up chromosomes | |
| 246841870 | nucleolus | a prominent structure within the non-dividing nucleus involved in the production of ribosomes | |
| 246841871 | ribosomes | complexes made of ribosomal RNA and protein which are the cellular components that carry out protein synthesis | |
| 246841872 | endomembrane system | consists of the nuclear envelope, the endoplasmic reticulum, the Golgi apparatus, lysosomes, various kinds of vesicles and vacuoles, and the plasma membrane | |
| 246841873 | vesicles | membrane sacs that specialize in moving products into, out of, and within a cell | |
| 246841874 | endoplasmic reticulum (ER) | an extensive network of membranes that accounts for more than half of the total membrane in many eukaryotic cells | |
| 246841875 | smooth ER | the outer surface lacks ribosomes | |
| 246841876 | rough ER | studded with ribosomes on the outer surface of the membrane | |
| 246841877 | glycoproteins | proteins that have carbohydrates covalently bonded to them | |
| 247229966 | transport vesicles | a small, membranous sac in a eukaryotic cell's cytoplasm carrying molecules produced by the cell | |
| 247229967 | Golgi apparatus | an organelle in eukaryotic cells consisting of stacks of flat, membranous sacs that modify, store, and route products of the ER and synthesize some products, notably noncellulose carbohydrates | |
| 247229968 | lysosome | a membrane-closed sac of hydrolydic enzymes found in the cytoplasm of animal cells and some protists | |
| 247229969 | phagocytosis | a type of endocytosis in which large, particulate substances or small organisms are taken up by the cell | |
| 247229970 | vacuole | a membrane-bound vesicle whose specialized function varies in different kinds of cells | |
| 247229971 | food vacuole | a membranous sac formed by phagocytosis of microorganisms or particles to be used as food by the cell | |
| 247229972 | contractile vacuole | a membranous sac that helps move excess water out of certain freshwater protists | |
| 247229973 | central vacuole | a large, membranous with diverse roles in growth, storage, and sequestration of toxic substances | |
| 247229974 | mitochondrion | an organelle in eukaryotic cells that serves as the site of cellular respiration; uses oxygen to break down organic molecules and synthesize ATP | |
| 247229975 | chloroplast | an organelle found in plants and photosynthetic that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water | |
| 247229976 | endosymbiont theory | the theory that mitochondria and chloroplasts originated as prokaryotic cells engulfed by an ancestral eukaryotic cell, which became its host cell and then evolved into a single organism | |
| 247229977 | crista | an infolding of the inner membrane of the mitochondrion; the inner membrane houses electron transport chains and molecules of the enzyme catalyzing the synthesis of ATP | |
| 247229978 | mitochondrial matrix | the compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the citric acid cycle, as well as ribosomes and DNA | |
| 247229979 | thylakoid | a flattened, membranous sac inside the chloroplast; they often exist in stacks called grana that are interconnected; their membranes contain molecular "machinery" used to convert light energy to chemical energy | |
| 247229980 | granum | a stack of membrane-bound thylakoids in the chloroplast, which function in the light reactions of photosynthesis | |
| 247229981 | stroma | the dense, fluid liquid within the chloroplast surrounding the thylakoid membrane and containing ribosomes and DNA; involved in the synthesis of organic molecules from carbon dioxide and water | |
| 247229982 | plastid | one of a family of closely related organelles that includes chloroplasts, chromoplasts, and amyloplasts | |
| 247229983 | peroxisome | an organelle containing enzymes that transfer hydrogen atoms from various substrates to oxygen, producing and then degrading hydrogen peroxide | |
| 247229984 | cytoskeleton | a network of microtubules, mircofilaments, and intermediate filaments that extend throughout the cytoplasm and serve a variety of mechanical, transport, and signal functions | |
| 247229985 | motor protein | a protein that interacts with cytoskeletal elements and other cell components, producing movement of the whole cell or parts of the cell | |
| 247229986 | microtubule | a hollow rod composed of tubulin proteins that makes up parts of the cytoskeleton | |
| 247229987 | centrosome | a structure present in the cytoplasm that functions as a microtubule-organizing center and is important during cell division; has two centrioles | |
| 247229988 | centriole | a structure in the centrosome composed of a cylinder of microtubule arranged in a certain pattern | |
| 247229989 | flagellum | a long cellular appendage specializing in locomotion | |
| 247229990 | cilium | a short appendage containing microtubules that is specialized for locomotion or moving fluid past the cell | |
| 247229991 | basal body | a eukaryotic cellular structure consisting of an arrangement of microtubule triplets; it may organize the microtubule assembly of a cilium or flagellum and is structurally similar to a centriole | |
| 247229992 | dyneins | In cilia and flagella, a large motor protein extending from one microtubule doublet to the adjacent doublet; ATP hydrolysis drives changes in dynein shape that lead to bending of cilia and flagella | |
| 247229993 | microfilament | A cable composed of actin proteins in the cytoplasm making up part of the cytoskeleton and acting alone or with myosin to cause cell contraction | |
| 247229994 | actin | A globular protein that links into chains, two of which twist helically about each other, forming microfilaments in muscle and other kinds of cells | |
| 247229995 | cortex | The outer region of cytoplasm, that has a more gel-like consistency than the inner regions due to the presence of multiple microfilaments | |
| 247229996 | myosin | a type of motor protein that associates into filaments that interact with actin filaments to cause cell contraction | |
| 247229997 | cytoplasmic streaming | A circular flow of cytoplasm, involving interactions of myosin and actin filaments, that speeds the distribution of materials within cell | |
| 247229998 | intermediate filament | A component of the cytoskeleton that includes filaments intermediate in size between microtubules and microfilaments | |
| 247229999 | cell wall | A protective layer external to the plasma membrane in the cells of plants, prokaryotes, fungi, and some protists; cellulose is an important structural component of cell walls | |
| 247230000 | primary cell wall | a relatively thin and flexible layer that surrounds the plasma membrane of a young cell | |
| 247230001 | middle lamella | a thin layer of adhesive extracellular material, primarily pectins, found between primary walls | |
| 247230002 | secondary cell wall | a strong and durable matrix that is often deposited in several laminated layers around the plasma membrane and provides protection and support | |
| 247230003 | extracellular matrix (ECM) | the meshwork surrounding animal cells, consisting of glycoproteins, polysaccharides, and proteoglycans synthesized and secreted by the cells | |
| 247230004 | collagen | a glycoprotein in the extracellular matrix of animal cells that forms strong fibers, found in connective tissue and bone; the most abundant protein in animals | |
| 247230005 | proteoglycan | a large molecule consisting of a small core protein with many carbohydrate chains attached, found in the extracellular matrix of animal cells | |
| 247230006 | fibronectin | an extracellular glycoprotein secreted by animal cells that helps them attached to the extracellular matrix | |
| 247230007 | integrin | a transmembrane receptor protein with two subunits that interconnects the extracellular matrix and the cytoskeleton | |
| 247230008 | plasmodesma | an open channel through the cell wall that connects the cytoplasm of adjacent plant cells, allowing water, small solutes, and some molecules to pass between the cells | |
| 247230009 | selective permeability | a property of biological membranes that allows them to regulate the passage of substances across them | |
| 247230010 | amphipathic | having both a hydrophilic region and a hydrophobic region | |
| 247230011 | fluid mosaic model | the currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of protein molecules drifting laterally in a fluid bilayer of phospholipids | |
| 247230012 | integral protein | a transmembrane protein with hydrophobic regions that extend into hydrophobic interior of the membrane and with hydrophilic regions in contact with the aqueous solution on one or both sides of the membrane | |
| 247230013 | peripheral protein | a protein loosely bound to the surface of a membrane or to part of an integral protein and not embedded in the lipid bilayer | |
| 247230014 | glycolipid | a lipid with one or more covalently attached carbohydrates | |
| 247230015 | glycoprotein | a protein with one or more covalently attached carbohydrates | |
| 247230016 | transport protein | a transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane | |
| 247230017 | aquaporin | a channel protein in the plasma membrane of a cell that specifically facilitates osmosis, the diffusion of free water across the membrane | |
| 247230018 | diffusion | the spontaneous movement of a substance down its concentration l gradient, from a region where it is more concentrated to a region where it is less concentrated | |
| 247230019 | concentration gradient | a region along which the density of a chemical substance increases or decreases | |
| 247230020 | passive transport | the diffusion of a substance across a biological membrane with no expenditure of energy | |
| 247230021 | osmosis | the diffusion of free water across a selectively permeable membrane | |
| 247230022 | tonicity | the ability of a solution surrounding a cell to cause that cell to gain or lose water | |
| 247230023 | isotonic | refers to a solution that, when surrounding a cell, causes no net movement of water into or out of the cell | |
| 247230024 | hypertonic | refers to a solution that, when surrounding a cell, will cause the cell to lose water | |
| 247230025 | hypotonic | referring to a solution that, when surrounding a cell, will cause the cell to take up water | |
| 247230026 | osmoregulation | regulation of solute concentrations and water balance by a cell or organism | |
| 247230027 | turgid | swollen or distended | |
| 247230028 | flaccid | limp and lacking stiffness or firmness | |
| 247230029 | plasmolysis | a phenomenon in walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall; occurs when the cell loses water to a hypertonic environment | |
| 247230030 | facilitated diffusion | the passage of molecules or ions down their electrochemical gradient across a biological membrane with the assistance of specific transmembrane transport proteins, requiring no energy expenditure | |
| 247230031 | ion channel | a transmembrane protein channel that allows a specific ion to diffuse across the membrane down its concentration or electrochemical gradient | |
| 247230032 | gated channel | a transmembrane protein channel that opens or closes in response to a particular stimulus | |
| 247230033 | active transport | the movement of a substance across a cell membrane against its concentration gradient, mediated by specific transport proteins and requiring an expenditure of energy | |
| 247230034 | sodium-potassium pump | a transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell | |
| 247230035 | membrane potential | the difference in voltage across a cell's plasma membrane due to the differential distribution of ions; membrane potential affects the activity of excitable cells and the transmembrane movement of all charged substances | |
| 247230036 | electrochemical gradient | the diffusion gradient of an ion, which is affected by both the concentration difference of an ion across a membrane and the ion's tendency to move relative to the membrane potential | |
| 247230037 | electrogenic pump | an active transport protein that generates voltage across a membrane while pumping ions | |
| 247230038 | proton pump | an active transport protein in a cell membrane that uses ATP to transport hydrogen ions out of a cell against their concentration gradient, generating a membrane potential in the process | |
| 247230039 | cotransport | the coupling of the "downhill" diffusion of one substance to the "uphill" transport of another against its own concentration gradient | |
| 247230040 | exocytosis | the cellular secretion of biological molecules by the fusion of vesicles containing them with the plasma membrane | |
| 247230041 | endocytosis | cellular uptake of biological molecules and particulate matter via formation of vesicles from the plasma membrane | |
| 247230042 | ligand | a molecule that binds specifically to another molecule, usually a larger one | |
