KREBS CYCLE

Here are two diagrams of the cycle, the second one is a little more complex than the previous one. The first one is at about the level of detail we need to know (also use the review questions as a guide):

simplest

more detail

Pyruvate enters the mitochondria, one carbon is removed, and the two-carbon fragment joins coenzyme A. Acetyl CoA then joins oxaloacetate already present from a previous "turn" of the cycle.

Functions of the Kreb Cycle:

• H+ and e- are transferred to NAD+ and FAD to become NADH and FADH₂, respectively.
• Two molecules of ATP are produced by substrate-level phosphorylation.
• Most of the molecules are recycled to conserve oxaloacetate for continuous processing of acetyl-CoA.

REVIEW: The Krebs cycle takes place in the
Answer mitochondria.