CELL RESPIRATION
THE KREBS CYCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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oxygen is present
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oxygen is not present
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glycolysis occurs
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carbon dioxide is present
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Detailed explanation-1: -The Krebs cycle, by itself, does not require the presence of oxygen; this element is necessary for the last stage of aerobic cellular respiration, i.e., oxidative phosphorylation. Organic molecules endowed with energy (carbohydrates, lipids, proteins) are split in previous reactions.
Detailed explanation-2: -Thus, if oxygen is not present, the respiratory cycle cannot function, which shuts down the Krebs cycle. For this reason, the Krebs cycle is considered an aerobic pathway for energy production.
Detailed explanation-3: -In the presence of oxygen organisms are capable of using the Kreb’s Cycle. The reason oxygen is required is because the NADH and [FADH2] produced in the Kreb’s Cycle are able to be oxydized in the electron transport chain (ETC) thus replenishing the supply of NAD+ and [FAD].
Detailed explanation-4: -Krebs cycle occurs in mitochondria only. Since mitochondria are not there in RBCs, Krebs cycle cant occur in RBCs.
Detailed explanation-5: -NADP is not formed during the krebs cycle.