Plasma Membrane Flashcards
Plasmolysis
shrinking of the cytoplasm away from the wall of a living cell due to outward osmotic flow of water
Cytolysis
the usually pathologic dissolution or disintegration of cells
Endocytosis
incorporation of substances into a cell by phagocytosis or pinocytosis
Diffusion
the process whereby particles of liquids, gases, or solids intermingle as the result of their spontaneous movement caused by thermal agitation and in dissolved substances move from a region of higher to one of lower concentration
Hypertonic
having a higher osmotic pressure than a surrounding medium or a fluid under comparison
Phagocyte
a cell (as a white blood cell) that engulfs and consumes foreign material (as microorganisms) and debris
Turgor pressure
pushes the plasma membrane against the cell wall of plant, bacteria, and fungi cells as well as those protist cells which have cell walls
Exocytosis
the release of cellular substances (as secretory products) contained in cell vesicles by fusion of the vesicular membrane with the plasma membrane and subsequent release of the contents to the exterior of the cell
Facilitated diffusion
is the process of spontaneous passive transport
Hypotonic
having a lower osmotic pressure than a surrounding medium or a fluid under comparison
Active transport
the movement of a chemical substance by the expenditure of energy against a gradient in concentration or in electrical potential across a plasma membrane
Osmosis
movement of a solvent (as water) through a semipermeable membrane (as of a living cell) into a solution of higher solute concentration that tends to equalize the concentrations of solute on the two sides of the membrane
Carrier protein
different carrier proteins that facilitate the diffusion of different molecules
Ion channel
a cell membrane channel that is selectively permeable to certain ions (as of calcium or sodium)
Equilibrium
a state of balance between opposing forces or actions that is either static (as in a body acted on by forces whose resultant is zero) or dynamic (as in a reversible chemical reaction when the rates of reaction in both directions are equal)
Vesicle
a membranous and usually fluid-filled pouch (as a cyst, vacuole, or cell) in a plant or animal
Pinocytosis
the uptake of fluid and dissolved substances by a cell by invagination and pinching off of the cell membrane
