Chapter 7 Vocab Flashcards
Amphipathic
Having both a hydrophilic region and a hydrophobic region
Selective permeability
A property of biological membranes that allows them to regulate the passage of substances
Fluid mosaic model
The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of protein molecules drifting laterally in s fluid bilayer of phospholipids
Integral protein
Typically a transmembrane protein with hydrophobic regions that extend into and often completely down the hydrophobic interior of the membrane and with hydrophilic regions in contact with the aqueous solution on either side of the membrane
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
Transport protein
A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane
Aquaporin
A channel protein in the plasma membrane of a plant, animal, or microorganism cell that specifically facilitates osmosis, the diffusion of water across the membrane
Diffusion
The spontaneous movement of a substance down its concentration gradient, from a region where it is more concentrated to a region where it is less concentrated
Concentration gradient
A region along which the density of a chemical substance increases or decreases
Passive transport
The diffusion of a substance across a biological membrane with no expenditure of energy
Osmosis
The diffusion of water across a selectively permeable membrane
Isotonic
Referring to a solution that, when surrounding a cell, HAS NO EFFECT ON THE PASSAGE OF WATER INTO OR OUT OF THE CELL
Hypertonic
Referring to a solution that, when surrounding a cell, WILL CAUSE CELL TO LOSE WATER
Hypotonic
Referring to s solution that, when surrounding a cell, WILL CAUSE THE CELL TO TAKE UP WATER
Turgid
SWOLLEN OR DISTENDED, as in plant cells
