[BIO 202] - Final Exam Guide - Everything you need to know! (51 pages long)
29 Nov 2016
School
Department
Course
Professor
Document Summary
Plasma membranes have selective permeability, only allowing hydrophobic (nonpolar) molecules like hydrocarbon to dissolve through the lipid bilayer membrane, and disallowing hydrophilic (polar) molecule like sugars to cross the membrane easily. Uniport involves the movement of a single substance in a single direction. Symport involves the movement of two different substances in the same direction. (co- transport) Antiport involves the movement of two different substances in opposite directions. (co- transport) Facilitated diffusion (passive transport) using carriers and channels. Diffusion is the net drift of molecules from high to low concentration due to random thermal movements. The concentration gradient itself represents the potential energy that drives diffusion. O2 diffuses because it is being used during respiration. During dynamic equilibrium, molecules cross in equal amounts in both directions. The smaller the molecule, the faster it diffuses than a larger molecule at a given temperature. The higher the temperature, the faster the diffusion rate.
