Explanation
The largest amount of phosphate bond energy is produced in the process of respiration during B: Krebs Cycle, also known as the citric acid cycle or the tricarboxylic acid cycle (TCA cycle). The Krebs Cycle takes place in the mitochondria and is a series of biochemical reactions that break down acetyl CoA, which is produced during the earlier stage of cellular respiration called glycolysis. The Krebs Cycle generates high-energy molecules in the form of NADH and FADH2, which are then used to produce ATP through oxidative phosphorylation. In total, the Krebs Cycle produces two ATP molecules, eight NADH molecules, and two FADH2 molecules per glucose molecule. This makes it the most energy-rich stage of cellular respiration, with the potential to produce up to 30-32 ATP molecules per glucose molecule through oxidative phosphorylation.
A: Glycolysis is the first stage of cellular respiration, and it breaks down glucose into two molecules of pyruvate. It produces a small amount of ATP and NADH.
C: Anaerobic respiration is a form of cellular respiration that takes place in the absence of oxygen. It produces a limited amount of ATP and is less efficient than aerobic respiration.
D: Fermentation is an alternative pathway that occurs when there is a lack of oxygen. It produces a limited amount of ATP and is less efficient than aerobic respiration.
