PHYL 1010X Lecture Notes - Lecture 1: Phagocytosis, Exocytosis
Document Summary
Membrane transport passive transport no input energy diffusion facilitated diffusion higher to lower concentration equilibrium active transport energy input needed primary active transport secondary active transport lower to higher concentration no equilibrium lipid bilayer nonpolar molecules oxygen, carbon dioxide, steroid and other lipid soluble hormones, fatty acids protein channel ions small polar molecules channel proteins diameter of pore electric charge in pore lining gated channels signals chemical mechanical electrical. Facilitated diffusion slower than diffusion passive transport no cellular energy input energy from concentration gradient net movement from higher to lower concentration net movement stops at equilibrium mediated transport carrier protein only open to one side at a time never creates a continuous channel molecules may be carried in either direction. Secondary active transport active transport energy input concentration gradient of other molecule lower to higher concentration no equilibrium mediated transport carrier protein co transport.