BSC1010C Chapter Notes - Chapter 6.3-6.4: Electrochemical Gradient, Osmosis, Active Transport
Document Summary
Diffusion is spontaneous movement of molecules and ions across a membrane: moves along the concentration gradient where when there is a net movement from regions of high concentration to regions of low concentration. Diffusion is high to low (cid:894)that"s its concentration gradient(cid:895: passive transport is the diffusion of molecules without the use of energy. Osmosis is movement of water across a membrane: here is a diagram showing how it effects blood cells. The fluid-mosaic model membranes are dynamic and has different types of proteins. Integral membrane proteins, (transmembrane proteins are proteins that face both interior and exterior sides of the cell. Peripheral membrane proteins are proteins that bind to membrane lipids or integral membrane proteins without passing through it. A detergent is a small amphipathic molecule that can form micelles and break down membrane. Ion channels form pores or openings in a membrane. Ions can diffuse from regions of a high concentration to regions of a low concentration.