Lecture 2B: Cell Membranes & Diffusion

I.                   Membrane Structure
A. Phospholipid bilayer
B. Transmembrane proteins (intrinsic, transport)
C. Cytoskeleton proteins
D. Exterior proteins (extrinsi, receptor, & recognition
E. Sanger & Nicholson: Fluid Mosaic Model
F. Selective Permeability

II. How substances cross cell membranes

A. Diffusion: concentration gradient
B. Osmosis

1. hydrostatic & osmotic pressure/extrusion & turgor/plasmolysis
2. hypotonic/ hypertonic/ isotonic

C. Bulk Passage: endocytosis & exocytosis
D. Facilitated diffusion (passive transport)
E. Active transport (Na/K pump)