A researcher is studying a specific type of cell that has a high metabolic rate and produces a large quantity of ATP through aerobic respiration. Upon microscopic examination, they observe that these cells contain an unusually high number of cristae within their mitochondria. This observation is consistent with:
- AEnhanced activity of the electron transport chain.
- BIncreased efficiency of glycolysis.
- CLower rate of ATP synthase function.
- DReduced demand for oxygen.
Show answer & explanationAnswer & explanation
Correct answer: A. Enhanced activity of the electron transport chain.
Cristae are the folds of the inner mitochondrial membrane where the electron transport chain (ETC) and ATP synthase complexes are located. An increased number of cristae provides a larger surface area for these protein complexes, directly correlating with an enhanced capacity for oxidative phosphorylation and thus a higher rate of ATP production via the electron transport chain.
Why the other options are wrong
- B. Glycolysis occurs in the cytoplasm and is not directly influenced by mitochondrial cristae count.
- C. More cristae would provide more sites for ATP synthase, suggesting a higher, not lower, rate of ATP synthesis.
- D. A high metabolic rate and high ATP production via aerobic respiration would imply an increased, not reduced, demand for oxygen.
Mitochondrial Cristae Function
Cristae are the numerous folds of the inner mitochondrial membrane that significantly increase the surface area available for the electron transport chain (ETC) and ATP synthase complexes. This increased surface area is crucial for efficient oxidative phosphorylation and ATP production.
- Folds of the inner mitochondrial membrane.
- Increase surface area for ETC and ATP synthase.
- Site of oxidative phosphorylation.
- Higher number indicates higher metabolic activity.
Memory trick: Cristae: 'Creases' for 'Capacity' in the 'Cell's energy factory.