A researcher is studying a specific type of cell that has a high metabolic rate and produces a large amount of ATP. Upon electron microscopic examination, these cells are found to have numerous mitochondria with highly folded inner membranes. What is the primary function of these folds, known as cristae, in the mitochondria?
- ATo provide a larger surface area for the electron transport chain components.
- BTo facilitate the transport of genetic material into the mitochondria.
- CTo increase the volume of the mitochondrial matrix for enzyme storage.
- DTo protect the mitochondrial DNA from oxidative damage.
Show answer & explanationAnswer & explanation
Correct answer: A. To provide a larger surface area for the electron transport chain components.
The cristae are the folds of the inner mitochondrial membrane. Their primary function is to dramatically increase the surface area available for the embedding of protein complexes and enzymes involved in the electron transport chain and oxidative phosphorylation, thereby maximizing ATP production.
Why the other options are wrong
- B. Mitochondria have their own DNA, and its transport is not the primary function of cristae.
- C. The cristae increase surface area, not primarily matrix volume, and enzymes for the Krebs cycle are in the matrix, not stored on cristae.
- D. While some protective mechanisms exist, increasing surface area for ATP production is the main role of cristae, not specific DNA protection.
Mitochondrial Cristae Function
The cristae are the numerous folds of the inner mitochondrial membrane that significantly increase its surface area. This expanded surface area is crucial for housing the protein complexes of the electron transport chain and ATP synthase, maximizing ATP production through oxidative phosphorylation.
- Folds of the inner mitochondrial membrane.
- Greatly increase surface area.
- Site of the electron transport chain and ATP synthase.
- Essential for efficient oxidative phosphorylation and ATP production.
Memory trick: Cristae: The 'creases' that create more space for energy.