This educational worksheet helps students visualize and understand the complex steps of the Krebs Cycle through a labeled diagram.

1. The Krebs cycle begins when acetyl-CoA combines with oxaloacetate to form citrate.
2. Citrate is converted to isocitrate through a rearrangement reaction.
3. Isocitrate is oxidized to alpha-ketoglutarate, producing NADH and releasing CO₂.
4. Alpha-ketoglutarate is further oxidized to succinyl-CoA, producing another NADH and releasing CO₂.
5. Succinyl-CoA is converted to succinate, generating GTP (or ATP) via substrate-level phosphorylation.
6. Succinate is oxidized to fumarate, producing FADH₂.
7. Fumarate is hydrated to malate.
8. Malate is oxidized back to oxaloacetate, producing the third NADH of the cycle.
9. Oxaloacetate is now ready to combine with another acetyl-CoA molecule to restart the cycle.
10. For each acetyl-CoA entering the cycle, the net yield is 3 NADH, 1 FADH₂, 1 GTP (or ATP), and 2 CO₂ molecules.