| A | B |
| actin | globular protein forming microfilaments in muscle |
| aminopeptidase | enzyme of small intestine that splits off one amino acid opposite from the free carboxyl group of a polypeptide |
| basal body | organelle consisting of a 9 + 0 arrangement of microtubule triplets of cilium/flagellu |
| cell fractionation | disruption of a cell and separation of its organelles by centrifugation |
| cell wall | protective layer external to the plasma membrane in plant cells |
| central vacuole | membranous sac in a mature plant cell with diverse roles in reproduction |
| centriole | animal cell structure made of cylinders of microtubule triplets arranged in a 9 + 0 pattern |
| centrosome | present in the cytoplasm of all eukaryotic cells |
| chloroplast | organelle that absorbs sunlight and uses it to make organic compounds from carbon dioxide and water |
| chromatin | complex of DNA and proteins that makes up a eukaryotic chromosome |
| chromosome | threadlike |
| cilium | short cellular appendage specialized for locomotion |
| collagen | glycoprotein in the extracellular matrix of animal cells that forms strong fibers |
| contractile vacuole | membranous sac that helps move excess water out of the cell |
| crista | infolding of the inner membrane of a mitochondrion that houses the electron transport chain |
| cytoplasm | entire contents of the cell |
| cytoplasmic streaming | circular flow of cytoplasm that speeds the distribution of materials within cells |
| cytoskeleton | network of microtubules |
| cytosol | semifluid portion of the cytoplasm |
| desmosome | type of intercellular junction in animal cells that functions as an anchor |
| dynein | large contractile protein forming the side-arms of microtubule doublets in cilia and flagella |
| electron microscope (EM) | microscope that focuses an electron beam through a specimen |
| transmission electron microscope (TEM) | used to study the internal structure of thin sections of cells |
| scanning electron microscope (SEM) | used to study the fine details of cell surfaces |
| endomembrane system | collection of membranes inside and around a eukaryotic cell |
| eukaryotic cell | type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles |
| extracellular matrix (ECM) | substance in which animal tissue cells are embedded |
| fibronectin | glycoprotein that helps cells attach to the extracellular matrix. |
| flagellum | long cellular appendage specialized for locomotion |
| food vacuole | membranous sac formed by phagocytosis |
| gap junction | intercellular junction of animal cells allows passage of material between cells |
| glycoprotein | protein covalently attached to a carbohydrate |
| Golgi apparatus | organelle made of stacks of flat membranous sacs that modify |
| granum | stacked portion of chloroplast thylakoid membrane functions in the light reactions of photosynthesis |
| integrin | receptor protein of plasma membrane interconnects extracellular matrix and cytoskeleton |
| intermediate filament | cytoskeleton filaments intermediate in size between microtubules and microfilaments |
| light microscope (LM) | optical instrument with lenses that refract (bend) visible light to magnify images of specimens |
| lysosome | membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of eukaryotic cells |
| microfilament | solid rod of actin protein in the cytoplasm causes cell contraction |
| microtubule | hollow rod of tubulin protein in the cytoplasm |
| middle lamella | adhesive extracellular material |
| mitochondrial matrix | compartment of the mitochondrion enclosed by the inner membrane with enzymes and substrates for the Krebs cycle |
| mitochondrion | organelle that serves as the site of cellular respiration. |
| myosin | protein filament that interacts with actin filaments to cause cell contraction |
| nuclear envelope | membrane that encloses the nucleus |
| nuclear lamina | netlike array of protein filaments that maintains the shape of the nucleus |
| nucleoid | dense region of DNA in a prokaryotic cell |
| nucleolus | structure in the nucleus active in the synthesis of ribosomes |
| nucleus | chromosome-containing organelle of a eukaryotic cell |
| organelle | bodies with specialized functions |
| peroxisome | microbody with enzymes to transfer hydrogen from various substrates to oxygen |
| phagocytosis | endocytosis involving large |
| plasma membrane | membrane at the boundary of every cell that acts as a selective barrier |
| plasmodesma | channel 0f cell wall through which strands of cytosol connect adjacent cell |
| plastid | family of closely related plant organelles (chloroplast |
| primary cell wall | relatively thin and flexible layer first secreted by a young plant cell |
| prokaryotic cell | cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles |
| proteoglycan | glycoprotein in the extracellular matrix of animal cells |
| pseudopodium | cellular extension of amoeboid cells used in moving and feeding. |
| ribosome | organelle constructed in the nucleolus and functioning as the site of protein synthesis |
| rough ER | portion of the endoplasmic reticulum studded with ribosomes |
| secondary cell wall | strong and durable matrix often deposited in several laminated layers for plant cell protection and support |
| smooth ER | portion of the endoplasmic reticulum that is free of ribosomes |
| stroma | fluid of chloroplast surrounding thylakoid membrane; involved in the synthesis of organic molecules |
| thylakoid | flattened membrane sac inside the chloroplast |
| tight junction | junction that prevents the leakage of material between cells |
| tonoplast | membrane encloses central vacuole separates cytosol from vacuolar contents (cell sap) |
| transport vesicle | tiny membranous sac in a cell’s cytoplasm carrying molecules produced by the cell |
| vesicle | sac made of membrane inside of cells |