BIOL-3510: Ch.15: Powering the Cell

In cellular catabolism:

glucose is oxidized in the cytosol and mitochondria to release energy

Food molecules are broken down in 3 stages

1. large food molecules are digested outside the cell

2. Starts with glycolysis in the cytosol, ends with acetyl CoA in the mitochondrial matrix

3. Begins with citric acid cycle in the matrix, ends with oxidative phosphorylation on the inner membrane

Glycolysis

glucose = 2 pyruvate + 2 ATP + 2 NADH

Pyruvate produced by glycolysis is:

actively pumped into the mitochondrial matrix

Pyruvate dehydrogenase complex

Converts pyruvate into acetyl CoA and CO2

Reduces NAD+ to NADH

Citric acid cycle

3 NADH + 1 GTP + 1 FADH2 + 2 CO2

Oxidative phosphorylation

NADH + FADH2 = ATP