Cell transport

what does the plasma membrane regulate?

flow of liquids, and dissolved solids and gases, in and out of the cell

types of cell transport

active transport and passive transport

types of active transport

endocytosis and exocytosis

phagocytosis and pinocytosis

types of passive transport

osmosis

simple and facilitated diffusion

simple diffusion

passive movement of substances from a higher concentration to a lower concentration

concentration gradient

a difference between concentrations

example of simple diffusion

during gas exchange in the alveoli, oxygen moves from being at higher concentrations in the air to a lower concentration in the blood

osmosis

a form of diffusion that involves the movement of solvent molecules (usually water)

net movement of water molecules from a solution with low solute concentration to a solution with a higher solute concentration

if the two solutions are the same concentration, there will be no net movement as they are isotonic to each other across a semi-permeable membrane

facilitated diffusion

involves large or charged molecules

can only move in or out of the cell with help from membrane proteins, down a concentration gradient

channel proteins open and close to allow specific substances through, and carrier proteins aid transport across the membrane