Cell Physiology Flashcards
movement of substance into and out of the cell
Membrane transport
homogeneous mixture of two or more components
Solution
dissolving medium
Solvent
components in smaller quantities within a solution
Solutes
fluid on the exterior of the cell
Interstitial fluid
nucleoplasm and cytosol
Intracellular fluid
The plasma membrane allows some materials to pass while excluding others
includes movement into and out of the cell
selective permeability
Particles tend to distribute themselves evenly within a solution.
Movement is from high concentration to low concentration, or down a concentration gradient
Diffusion
simple diffusion of water
Highly polar water easily crosses the plasma membrane
Osmosis
Water and solutes are forced through a membrane by fluid, or hydrostatic pressure
Filtration
Unassisted process
Solutes are lipid-soluble materials or small enough to pass through membrane pores
Simple diffusion
Substances require a protein carrier for passive transport
Facilitated diffusion
ATP energizes protein carriers, and in most cases, moves substances against concentration gradients
Solute pumping
Extracellular substances are engulfed by being enclosed in a membranous vesicle
Endocytosis
Two types of bulk transport
Exocytosis and Endocytosis