Question

The electron transport system is present in the

• A. Inner mitochondrial membrane
• B. Outer mitochondrial membrane
• C. Outer chloroplast membrane
• D. Mitochondrial matrix

Hint:

• ETS (respiration) → Inner mitochondrial membrane
• Photosynthetic ETC → Thylakoid membrane

Answer 1

The Correct Option is A

Concept: The electron transport system (ETS) is a series of protein complexes involved in oxidative phosphorylation.
• Located in the inner mitochondrial membrane
• Includes complexes I, II, III, IV and ATP synthase

Step 1: Analyzing each option.

• Inner mitochondrial membrane: Site of ETS → Correct.
• Outer mitochondrial membrane: Not involved in electron transport → Incorrect.
• Outer chloroplast membrane: Not the site of photosynthetic ETC (that occurs in thylakoid membrane) → Incorrect.
• Mitochondrial matrix: Contains enzymes of TCA cycle, not ETS → Incorrect.

Step 2: Selecting the correct answer.
Thus, the electron transport system is located in the inner mitochondrial membrane.