E1: Organelles

2 membranes which create three spaces:

1. The cytoplasm
2. The intermembrane space
3. The inner mitochondiral matrix

The mitochondria is the site of aerobic metabolism. The citric acid cycle crackles along in the inner matrix, producing electron donators that reduce the cytochrome enzymes in the inner membrane proteins, which pumps hydrogen ions into the intermembrane space to power ATP synthase.

The inner matrix is also the site of beta-oxydation and haem synthesis.

Lipids (50%):

• Phospholipid Bilayer, polar phosphate group and nonpolar fatty acid tail;
• Choelsterol, provides rigidity

Proteins (50%)

1. Surface proteins
2. Receptors → Δ cell fn when bound by ligands
3. Enzymes → Catalysing reactions
4. Cell adhesion molecules → anchor cells to neighbours or basal laminas
5. Integral Proteins → provide stability
6. Transmembrane Proteins
7. Ion Channels/Carriers → passive transport
8. Pumps → active transport; maintain homeostasis