Where are the molecules of the mitochondrial electron transport chain located?

• A. In the mitochondrial matrix
• B. In the outer mitochondrial membrane
• C. In the inner mitochondrial membrane
• D. In the intermembrane space

Answer: (C)

Verified step by step guidance

1. Understand the structure of the mitochondrion: The mitochondrion has several compartments, including the outer mitochondrial membrane, the inner mitochondrial membrane, the intermembrane space, and the mitochondrial matrix. Each compartment has specific functions.
2. Learn the role of the electron transport chain (ETC): The ETC is a series of protein complexes and molecules that transfer electrons to generate a proton gradient, which drives ATP synthesis during oxidative phosphorylation.
3. Identify the location of the ETC: The protein complexes and molecules of the ETC are embedded in the inner mitochondrial membrane. This membrane is highly folded into structures called cristae, which increase its surface area for efficient energy production.
4. Understand why the inner mitochondrial membrane is ideal: The inner membrane is impermeable to most ions and molecules, allowing the establishment of a proton gradient between the intermembrane space and the mitochondrial matrix. This gradient is essential for ATP synthesis.
5. Confirm the correct answer: Based on the structure and function of the mitochondrion, the molecules of the electron transport chain are located in the inner mitochondrial membrane.