AP BIOLOGY

Detailed explanation-1: -The Kreb Cycle has a total of 8 metabolic reactions involved in the full oxidation of our food molecules into carbon dioxide. 8 major reactions occur in the Kreb Cycle.

Detailed explanation-2: -Reaction 7: Hydrolysis of Succinyl CoA; This is the only “visible” ATP formed in the entire cycle. Succinic acid, a 4 carbon acid, is the product of this reaction. This is the start of the return to the beginning of the cycle. This reaction is catalyzed by succinyl CoA.

Detailed explanation-3: -Step 7. In step seven, water is added to the four-carbon molecule fumarate, converting it into another four-carbon molecule called malate. Step 8. In the last step of the citric acid cycle, oxaloacetate-the starting four-carbon compound-is regenerated by oxidation of malate.

Detailed explanation-4: -The TCA cycle is a set of eight catalyzed reactions and eight intermediates that break down hydrocarbon substrates into carbon dioxide (CO2) and water (H2O) using the energy released to protonate nicotinamide adenine dinucleotide converting from NAD+ to NADH or flavin adenine dinucleotide from FADH to FADH2.