Answer:
C. 10 ATP molecules
Explanation:
In the citric acid cycle is a series of eight reactions steps in which a two-carbon molecule, acetyl-CoA, enters the cycle through citrate and two atoms of carbon are removed as two molecules of carbon dioxide.
The energy generated by the complete oxidation of one molecule of acetyl CoA via the citric acid cycle is conserved in the production of three NADH molecules, one FADH₂ and one ATP molecule. Each NADH molecule transfers two electrons to oxygen in the electron transport chain, forming 2.5 ATP molecules each in the process. Similarly, an FADH2 molecules transfers two electrons to oxygen in the electron transport chain yielding 1.5 ATP molecules.
Total ATP molecules produced:
3 NADH + 1 FADH2 + 1 ATP = (2.5 × 3) + (1.5 × 1) + 1 ATP = 10 ATP molecules
Therefore, 10 ATP molecules are generated by the complete oxidation of one molecule of acetyl CoA via the citric acid cycle.
Answer:
B. Brain stem
Explanation:
The brain stem controls basic body functions such as breathing, swallowing, heart rate, blood pressure, consciousness, and whether one is awake or sleepy.
Answer:
At the beginning, aerobic respiration is used by his legs to generate energy when there was still sufficient oxygen intake for energy to be generated via oxidative phosphorylation.
Towards the end of the ride, his legs are generating energy through anaerobic respiration due to insufficient oxygen intake to keep up with the energy requirement of his muscles as he cycles continuously. Through anaerobic respiration, pyruvate from glycolysis is converted to lactate by lactate dehydrogenase instead of being channelled to the mitochondria for oxidative phosphorylation. The accumulation of lactate in his muscles is what causes the pain in his leg. After he stops the activity, the pain would reduce as lactate is transported to the liver to be reconverted back into pyruvate.
