Question

Describe what is happening during the Kreb’s cycle. Make sure you include all compounds made and in the correct order.

Answer 1

The citric acid cycle occurs in mitochondrial matrix; it consumes 2 water molecules (H₂O), and generates two carbon dioxide (CO₂) molecules along with one GTP molecule as a direct energy source. But no direct ATP is produced in the citric acid cycle.

Citric acid cycle also generates three NADH (reduced nicotinamide adenine dinucleotide), and one FADH₂ (reduced flavin adenine dinucleotide) by the oxidation of acetyl CoA.

The overall reaction of citric acid cycle for one acetyl CoA is,

Acetyl CoA + 3 NAD+ + FAD + GDP + Pi + 2 H₂O ----> 2 CO₂ + 3 NADH + FADH₂ + CoA SH + GTP + 3 H⁺

Where,

NAD⁺ – Nicotinamide adenine dinucleotide

FAD – Flavin adenine dinucleotide

GDP – Guanine adenine dinucleotide

NADH – reduced nicotinamide adenine dinucleotide

FADH2 – reduced flavin adenine dinucleotide