Krebs cycle and electron transport chain

These are notes from lecture 8 of Harvard Extension’s biochemistry class.

quick review of mitochondrial structure

To understand this post, it’s useful to know the mitochondrial structure (see also Cell Biology 03).

Here’s a rad CC BY Wikimedia Commons diagram by Kelvinsong & Sowlos:

citric acid cycle

Khan Academy’s introduction:

The citric acid cycle or Kreb’s cycle is the cell’s metabolic hub, as it not only generate energy from pyruvate (the product of glycolysis) but along the way also can consume and produce metabolites relevant to host of other processes.

Oxidative phosphorylation

It’s called a “cycle” and not a “pathway” because it both begins and ends with oxaloacetate. It takes place inside the mitochondrial matrix.

Pyruvate from glycolysis does not enter directly into the citric acid cycle.

First it passes through a “transition phase” where it is undergoes oxidative decarboxylation to CO₂ at the hands of