the membrane structure: decipting a cellular membrane as a mosaic of diverse protein molecules, embedded in a bilayer of phospholipid molecules
happens when the biological membranes allows some substances to cross more easily than others and blocks the passage of other substances altogether
spontaneous movement of a substance down its concentration gradient from where it is more concentrated to where it is less concentrated.
a region along which the density of a chemical substance increases or decreases.
-> when this exists, substances tend to move from where they are more concentrated to where they are less concentrated.
the diffusion of a substance across a biological membrane, with NO expenditure of energy.
The diffusion of water across a selectively permeable membrane.
The ability of a solution surrounding a cell to cause a cell to gain or lose water
Referring to a solution that, when surrounding a cell, has no effect on the passage of water into or out of a cell
Reffering to a solution that, when surrounding a cell, will cause the cell to take up water
an organisms whose body fluids have a solute concentration equal to that of its surroundings.
-do not have a net gain or loss of water by osmosis.
The passage of a substance through a specific transport protein across a biological membrane down its concentration gradient
the movement of a substance across a biological membrance against its concentration gradient, aided by specific transport proteins. REQUIRES ENERGY
Cellular uptakes of molecules or particles via formation of new vesicles from the plasma membrane.
The movement of materials out the cytoplasm of a cell by the fusion of vesicles with the plasna membrane.
Cellular "eating; a type of endocytosis in which a cell engulfs macromolecules
Cellular drinking. a type of endocytosis in which the cell takes fluid and dissolved solutes into small membranous vesicles.
The movement of specific molecules into a cell by the inward budding of a membranous vesicle, which contains proteins with recepto sites specific to the molecules taken in.
a protein channel- transport protein in the plasma membrane of some plant or animal cells that facilitates the diffusion of the water across the membrane