Question

Compare the role of following minerals with the given enzyme activities and identify the exact match.
\includegraphics[width=0.6\linewidth]{png}

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

Hint:

Key metalloenzyme markers to memorize:
- Carbonic Anhydrase = Zinc
- Glutathione Peroxidase = Selenium
- Cytochrome Oxidase = Copper

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Many enzymes require metal ions or minerals as cofactors to stabilize their structure or catalyze biochemical reactions.
These metalloproteins rely on the chemical properties of specific minerals to function properly.

Step 2: Detailed Explanation:
Let us match each mineral to its corresponding enzyme or biological activity:
A. Zinc: Zinc is an essential cofactor for several enzymes, including carbonic anhydrase.
In carbonic anhydrase, a zinc ion ($Zn^{2+}$) is coordinated by three histidine residues, where it activates a water molecule to catalyze the reversible hydration of carbon dioxide. This matches with IV.
B. Selenium: Selenium is covalently integrated as selenocysteine into the active site of glutathione peroxidase.
This antioxidant enzyme protects cells from oxidative damage by reducing hydrogen peroxide to water. This matches with I.
C. Fluoride: Fluoride is a well-known inhibitor of the glycolytic enzyme enolase. It binds with magnesium to block the enzyme's active site. This matches with II.
D. Copper: Copper ions ($Cu^{2+}/Cu^{+}$) act as electron carriers in redox enzymes.
Cytochrome c oxidase (Complex IV of the electron transport chain) contains copper centers ($Cu_{A}$ and $Cu_{B}$) that help transfer electrons to oxygen. This matches with III.
Matching these pairs results in: A-IV, B-I, C-II, D-III.

Step 3: Final Answer:
The correct matches are A-IV, B-I, C-II, and D-III, which corresponds to Option (A).