Question

Krebs cycle

Starting with one molecule of pyruvate and ending with oxaloacetate, how many ATP molecules and NADH and FADH2 are formed in citric acid cycle

Answer 1

• from pyruvate on NADH is produced
• Most of the energy made available by the oxidative steps of the cycle is transferred as energy-rich electrons to NAD⁺, forming NADH. For each acetyl group that enters the citric acid cycle, three molecules of NADH are produced.
• electrons from the succinate oxidation step are transferred first to the FAD cofactor of succinate dehydrogenase, reducing it to FADH₂,
• totally 4 NAHD, 1 FADH2 are formed
• For every NADH and FADH₂ that are produced in the citric acid cycle, 2.5 and 1.5 ATP molecules are generated in oxidative phosphorylation, respectively.
• 4 NADH*2.5 ATP=10 ATP
• 1 FADH2 * 1 ATP = 1.ATP
• 1 GTP = 1 ATP
• totally 12 ATP are formed in kerbs cycle from one pyruvate.