Question

Which of the following molecule is known as the energy currency of the cell

• A. ATP
• B. AMP
• C. NADH
• D. FADH$_2$

Hint:

Think of NADH as a "check" that needs to be cashed at the bank (Mitochondria) to get "cash" (ATP).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the specific molecule that serves as the primary medium for energy transfer within biological cells.
Detailed Explanation:

• ATP (Adenosine Triphosphate): It is often called the "energy currency" of the cell. This is because it stores readily usable energy in its high-energy phosphate bonds.

• Mechanism: When a cell needs energy for metabolic work (like muscle contraction or active transport), it breaks down ATP into ADP (Adenosine Diphosphate) and inorganic phosphate, releasing energy in the process.

• Comparison:
- AMP (B): Has only one phosphate; represents a lower energy state.
- NADH (C) and FADH$_2$ (D): These are electron carriers. They store energy during respiration, but this energy must first be converted into ATP (via the Electron Transport Chain) before it can be used for most cellular tasks.
Final Answer:
ATP is the molecule that directly powers cellular processes, making it the universal energy currency.