Question

Enzymes that utilize ATP in phosphate transfer require an alkaline earth metal (M) as the cofactor. M is:

• A. Be
• B. Mg
• C. Ca
• D. Sr

Answer 1

The Correct Option is B

To determine which alkaline earth metal acts as a cofactor for enzymes that utilize ATP in phosphate transfer, we need to understand the role of these metals in biological systems.

1. Enzyme and ATP Interaction: Enzymes that facilitate phosphate transfer from ATP often require a cofactor to stabilize the negatively charged phosphate groups. ATP (Adenosine Triphosphate) is a molecule that stores and transfers energy in cells, and this energy is released through the cleavage of phosphate bonds.
2. Role of Magnesium (Mg): Magnesium is a crucial mineral in biology because it serves as a cofactor for many processes, especially those involving ATP. The Mg²⁺ ion binds to the phosphate groups of ATP, reducing the negative charge and stabilizing the molecule. This binding is essential to activate ATP for enzyme-catalyzed reactions.
3. Why Not Other Options:
   • Be (Beryllium): Beryllium is not commonly used in biological systems due to its toxicity.
   • Ca (Calcium): While calcium plays important roles in biological processes, particularly in signaling and bone formation, it does not typically function as a cofactor for enzymes in ATP-dependent processes.
   • Sr (Strontium): Strontium is similar to calcium in some respects but is not used as a cofactor for enzymes in ATP-related biochemical processes.

Based on this understanding, Magnesium (Mg) is the correct answer as it is the alkaline earth metal cofactor required by enzymes utilizing ATP for phosphate transfer.