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| smallest unit with the properties of life: a capacity for metabolism, controlled responses to the environment, growth, and reproduction |
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| outer cell membrane; the structural and functional boundary between cytoplasm and extracellular fluid |
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| large organelle with an outer envelope of two pore-ridden lipid bilayers that separates eukaryotic chromosomes from the cytoplasm |
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| the portion of a prokaryotic cell where DNA is physically organized but not enclosed in a membrane |
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| all cell parts, particles, and semifluid substances between the plasma membrane and the nucleus or nucleoid |
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| structural basis of all cell membranes; mainly phospholipids arranged tail-to-tail in two layers, with hydrophilic heads of one dissolved in cytoplasmic fluid and the heads of the other in extracellular fluid |
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| the site of polypeptide chain synthesis in all cells. An intact ribosome has two subunits of rRNA and proteins |
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| a relationship in which the volume of an object increases with the cube of the diameter, but the surface area increases with the square |
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| physically separate chemical reactions, may of which are incompatible; organize metabolic events |
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| A small, membrane-bound sac in the cytoplasm; different sacs transport or store substances or hold enzymes that digest their contents |
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| a double membrane that is the outer boundary of the nucleus |
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| in an interphase nucleus, a mass of material from which RNA and proteins are assembled into the subunits of ribosomes |
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| Endoplasmic reticulum (ER) |
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| organelle that extends from the nuclear envelope through cytoplasm. Ribosomes coat the cytoplasmic side of rough ER, which modifies many new polypeptide chains in its lumen. Membrane lipids are assembled, fatty acids are broken down, and some toxins are inactivated in the lumen of smooth ER |
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| site of final modification of proteins, lipids; sorting and packaging them for used inside cell or for export |
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| vesicle filled with enzymes that functions in intracellular digestion |
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| enzyme-filled vesicle that breaks down amino acids, fatty acids, and toxic substances such as ethanol |
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| double-membraned organelle of ATP formation; only site of the second and third stages of aerobic respiration |
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| organelle of photosynthesis in plants and algae. Two outer membranes enclose a semifluid interior, the stroma. A third membrane forms a compartment inside that functions in ATP and NADPH formation; sugars form in the stroma |
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| in many mature, living plant cells, an organelle that stores amino acids, sugars, and some wastes; when it enlarges during growth, it forces the cell to enlarge and increase its surface area |
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| of many cells (not animal cells) a semirigid but permeable structure that surrounds the plasma membrane; helps a cell retain its shape and resist rupturing |
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| the first thin, pliable wall of young plant cells |
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| a rigid, permeable wall inside the primary wall of many plant cells; forms after the first growing season |
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| of a tissue, any molecular structure that connects adjoining cells physically, chemically, or both at their plasma membranes |
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| in a eukaryotic cell, the dynamic framework of diverse protein filaments that structurally support, organize, and move the cell and internal structures. Prokaryotic cells have a few similar protein filaments |
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| largest cytoskeletal element; a filament of tubulin subunits. Contributes to cell shape, growth, and function |
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| the thinnest cytoskeletal element; consists of actin subunits that function in cell contraction, movement, and structural support |
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| cytoskeletal element that mechanically strengthens some cells |
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| a dynamic mesh of crosslinked cytoskeletal elements just underneath the plasma membrane and attached to it |
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| of many eukaryotic cells, a long, whip-like motile structure with an inner 9 + 2 array of microtubules. prokaryotic flagella do not have this array and are not whip-like; they rotate like a propeller |
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| a motile structure with a 9 + 2 array of microtubules that projects from the plasma membrane of certain eukaryotic cells. Modified cilia, such as those of hair cells, have sensory functions |
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| a barrel-shaped structure that arises from a centrosome and organizes newly forming microtubules into a 9 + 2 array inside a cillium or flagellum |
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| an organelle that strated out as a centiole, the source of a 9 + 2 array of microtubules in a cillium or flagellum. It remains below the finished array |
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| a dynamic lobe of membrane-enclosed cytoplasm; functions in motility and phagocytosis by amoebas, amoeboid cells, and many white blood cells |
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