Question

The products in citric acid cycle are A. NADH B. GTP C. FADH2 D. pyruvate E. acetyl Co-A OC.DE A,B,C ОА, В ACE

Answer 1

Answer-

According to the given question-

• We know that during Glycolysis one molecule of glucose is metabolized into two molecules of pyruvate anaerobically into the cytosol, through a series of the enzymatic reactions and ATP was synthesized. But the large amounts of ATP are obtained through aerobic metabolism of glucose, which is done by complete oxidation of glucose into carbon dioxide, through the citric acid cycle or TCA or tricarboxylic acid cycle or Krebs cycle.
• The citric acid cycle is a common pathway for oxidation of several fuel molecules such as carbohydrates, fatty acids, and amino acids, and the molecules which enter the citric acid cycle is acetyl coenzyme A. thus Under aerobic conditions, molecules of pyruvate produced from glucose during the Glycolysis is oxidatively decarboxylated into Acetyl CoA, inside the mitochondria in eukaryotes.
• During the citric acid cycle, a series of oxidation-reduction reactions take place, which leads oxidation of the acetyl group of Acetyl Co-A into the two molecules of CO₂.
• During the citric acid cycle, oxaloacetate, a 4 –C compound condenses with Acetyl Co A, a 2 –C molecule into citrate or tricarboxylic acid, a 6- C molecule. Then Isocitrate is oxidatively decarboxylated, producing α-ketoglutarate, 1 5 –C compound, which yields succinate, a 4- C compound through oxidative decarboxylation, then the molecule of Oxaloacetate is regenerated from succinate. Thus in the citric acid cycle, 2 –C atoms enter the cycle in the form of Acetyl Co-A and leaves in the form of CO_2, 2 –C molecules.
• six electrons or 3 hydride ions are transferred to 3 molecules of NAD⁺ or nicotinamide adenine dinucleotide and 2 electrons or a pair of hydrogen atoms are transferred to 1 molecule of FAD or flavin adenine dinucleotide.
• Thus the citric acid cycle takes electron form Acetyl CoA and form NADH and FADH₂. Thus the citric acid cycle oxidizes Acetyl CoA and produces 2 molecules of carbon dioxide, 1 GTP molecule, NADH, and FADH₂.

Thus the correct answer is (B), NADH, GTP, and FADH₂