L16: Membrane Transport

Question 1

3 transport mechanism

Answer 1

1. Diffusion (passive)
   - simple (lipid-soluble compounds, dissolved gases)
   - channel-mediated (water-soluble compounds: size, charge, interaction with channel)
   - osmosis: osmotic pressure = hydrostatic pressure —> no osmotic flow
2. Carrier-mediated (active/passive)
   - facilitated diffusion (down conc gradient: glucose/amino acids carrier)
   - active transport (against conc gradient)
   —> primary: ion pumps/exchange pump
   —> secondary: glucose/amino acids
3. Vesicular (active)
   - endocytosis (receptor mediated, pinocytosis, phagocytosis)
   - exocytosis

Question 2

Diffusion depends on

Answer 2

1. Size
2. Temperature
3. Gradient
4. Distance
5. Electrical force