Where do the reactions of the electron transport chain occur in eukaryotic cells?

• A. Nuclear envelope
• B. Outer mitochondrial membrane
• C. Cytoplasm
• D. Inner mitochondrial membrane

Answer: (D)

Verified step by step guidance

1. Understand the concept 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 is used to produce ATP during cellular respiration.
2. Identify the location of cellular respiration in eukaryotic cells: Cellular respiration primarily occurs in the mitochondria, which is the powerhouse of the cell.
3. Learn the structure of the mitochondrion: The mitochondrion has several key components, including the outer mitochondrial membrane, the inner mitochondrial membrane, the intermembrane space, and the matrix.
4. Determine the specific location of the ETC: The protein complexes and molecules involved in the ETC are embedded in the inner mitochondrial membrane. This membrane is crucial because it separates the matrix from the intermembrane space, allowing the proton gradient to form.
5. Confirm the correct answer: Based on the above information, the reactions of the electron transport chain occur in the inner mitochondrial membrane of eukaryotic cells.