This diagram illustrates the circular structure of a plasmid vector, highlighting specific gene locations and regulatory elements used in genetic engineering.

- Identify the central molecule in the cycle: Acetyl-CoA.
- Recognize the first reaction: Acetyl-CoA combines with oxaloacetate to form citrate.
- Note the enzyme catalyzing this step: Citrate synthase.
- Follow the conversion of citrate to isocitrate via aconitase.
- Observe the oxidative decarboxylation of isocitrate to alpha-ketoglutarate, producing NADH and CO2.
- Identify the next step: Alpha-ketoglutarate is converted to succinyl-CoA, producing another NADH and CO2.
- Note the substrate-level phosphorylation: Succinyl-CoA is converted to succinate, generating GTP (or ATP).
- Track the oxidation of succinate to fumarate, producing FADH2.
- Recognize the hydration of fumarate to malate.
- Confirm the final step: Malate is oxidized back to oxaloacetate, producing NADH.
- Summarize the net output per acetyl-CoA: 3 NADH, 1 FADH2, 1 GTP (or ATP), and 2 CO2.
- Emphasize that oxaloacetate is regenerated to continue the cycle.