Double layer of phospholipids with proteins embedded Active Transport Bulk Transport Structure – Double layer of phospholipids with proteins embedded Function – Protection Regulate movement of materials into and out of membrane “selectively permeable”

3. Facilitated Diffusion Active Transport Bulk Transport Cell does not use energy H → L Types: Diffusion ex: O2 and CO2 2. Osmosis ex: H2O 3. Facilitated Diffusion ex: glucose Requires carrier protein

Active Transport Cell uses energy L → H Requires carrier protein Bulk Transport Cell uses energy L → H Requires carrier protein molecule Ex: “pumps” Na – K pump

Bulk Transport Molecules are too large Transported in vesicles Types: Active Transport Bulk Transport Molecules are too large Transported in vesicles Types: 1. Exocytosis Secretion of proteins 2. Endocytosis Phagocytosis - “cell eating” WBC eating bacteria Pinocytosis - “cell drinking”