Membrane Transport

I. Selective Permeability of the Phospholipid Bilayer (PL) A. What is permitted to cross B. What needs a transport protein due to poor or highly impermeant nature C. "Specificity designed by type of proteins but rate and direction of flow designed by its concentration gradient" D. Introduction to Simple Diffusion 1. Random walk theory; Brownian movement 2. Does NOT require energy 3. Solutes move down a concentration gradient II. Passive Transport A. Simple diffusion across a membrane 1. Concentration gradients 2. Equilibrium B. Osmosis 1. Isotonic 2. Hypertonic 3. Hypotonic C. Facilitated Diffusion 1. Saturation 2. Types of Facilitated diffusion a. aquaporins b. gated channels 1. opened by voltage 2. opened by ligands III. Active Transport A. Phosphorylation by ATP and energy requirement B. Sodium/Potassium ATPase pump C. Co-Transport (Secondary Active Transport)