Citric Acid (Krebs) Cycle

1.

acetyl-coA formation

2.

Two carbon atoms are transferred from acetyl-CoA to oxaloacetate (4-carbon). CoA is regenerated and citrate (6-carbon) forms.

3.

e- and H+ transferred from an intermediate to NAD+ (forms NADH). Oxidizing intermediate causes it to lose a carbon atom (leaves as CO2).

4.

A carbon atom is removed from an intermediate, released e- and H+ transferred to NAD+ (forms NADH). Carbon atoms leaves as CO2.

5.

One ATP forms by substrate-level phosphorylation.

6.

e- and H+ transferred from an intermediate to coenzyme FAD (forms FADH2).

7.

e- and H+ transferred from an intermediate to coenzyme NAD+ (forms NADH).

8.

Oxaloacetate is regenerated.