Question

Match LIST-I with LIST-II
\begin{tabularx}{0.8\textwidth}{|l|X|l|X|} \hline \multicolumn{2}{|c|}{LIST-I} & \multicolumn{2}{c|}{LIST-II}
\multicolumn{2}{|c|}{Mitochondrial Compartments} & \multicolumn{2}{c|}{Enzymes present}
\hline A. & Matrix & I. & ATP synthetase
B. & Inner membrane & II. & Monoamine oxidase
C. & Space between inner and outer membranes & III. & Citrate synthetase
D. & Outer membrane & IV. & Adenylate kinase
\hline \end{tabularx}
Choose the most appropriate answer from the options given below:

• A. A - IV, B - II, C - III, D - I
• B. A - III, B - I, C - IV, D - II
• C. A - II, B - I, C - IV, D - III
• D. A - I, B - IV, C - III, D - II

Hint:

Associate the main function with the compartment to remember enzyme locations:

\textbf{Matrix} \(\rightarrow\) Krebs Cycle \(\rightarrow\) Citrate Synthetase.
\textbf{Inner Membrane} \(\rightarrow\) ATP Production \(\rightarrow\) ATP Synthase.
\textbf{Outer Membrane} \(\rightarrow\) Acts as a boundary, has specific enzymes like Monoamine Oxidase.
\textbf{Intermembrane Space} \(\rightarrow\) "In-between" reactions \(\rightarrow\) Adenylate Kinase. \end{itemize}

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The mitochondrion is a double-membraned organelle with distinct compartments, each having a specific set of enzymes to carry out its functions in cellular respiration and metabolism. This question tests knowledge of the localization of specific mitochondrial enzymes.

Step 2: Detailed Explanation:
Let's match each mitochondrial compartment with its characteristic enzyme.
- A. Matrix: The innermost compartment, the matrix, is the site of the Krebs cycle (citric acid cycle) and fatty acid oxidation. Citrate synthetase is the enzyme that catalyzes the first step of the Krebs cycle. Therefore, it is located in the matrix. (A \(\rightarrow\) III).
- B. Inner membrane: This membrane is highly folded into cristae and is the site of the electron transport chain and oxidative phosphorylation. ATP synthetase (also called ATP synthase or Complex V) is embedded in the inner mitochondrial membrane, where it uses the proton gradient to produce ATP. (B \(\rightarrow\) I).
- C. Space between inner and outer membranes (Intermembrane space): This space contains several enzymes that use the ATP passing out of the matrix. Adenylate kinase is a phosphotransferase enzyme found here that catalyzes the reaction \(2 \text{ ADP} \rightleftharpoons \text{ATP} + \text{AMP}\). (C \(\rightarrow\) IV).
- D. Outer membrane: The outer membrane is quite permeable and contains various enzymes, including Monoamine oxidase, which is involved in the breakdown of neurotransmitters. (D \(\rightarrow\) II).

Step 3: Final Answer:
The correct pairings are: A-III, B-I, C-IV, D-II. This combination matches option (B).