Cell membranes and transport
I. Purpose of membranes - cellular and organelle
A. Continuum of systems - nucleus and endoplasmic reticulum
1. "Flow of metabolites"
B. Isolation - mitochondrion cannot fuse with nucleus
2. "Independent recognition sites"
C. Passage of metabolites
1. Diffusion - from high concentration to low concentration
2. Osmosis - movement of water through a differentially permeable membrane
a) From high concentration to low concentration
b) Selectivity - active transport
3. Carrier systems
1) H pumped into thylakoid lumen
2) H then transported to outer stroma and coupled to make ATP
1) H pumped out to intermembrane space
2) H then transported to inner matrix and coupled to make ATP
II. How is specific transport accomplished?
A. Biological membranes