What is the main energy currency of the cell?

• A. NADH
• B. FADH2
• C. ATP
• D. GTP

Answer: (C)

The main energy currency of the cell is ATP (adenosine triphosphate). ATP plays a crucial role in cellular metabolism by providing the energy required for various biological processes. It is synthesized through cellular respiration and is utilized by the cell for processes such as muscle contraction, neurotransmission, and biosynthesis of macromolecules.

ATP consists of an adenine base, a ribose sugar, and three phosphate groups. The bonds linking the phosphate groups are high-energy bonds, and when ATP is hydrolyzed, it releases energy that can be harnessed for work within the cell. This makes ATP uniquely versatile as it can readily transfer energy to different cellular processes.

While NADH and FADH2 are important electron carriers that shuttle electrons in cellular respiration, and GTP also serves as an energy currency in some specific pathways (such as protein synthesis), ATP is the most widely utilized form of energy across various cellular functions, thus establishing its role as the primary energy currency in all living cells.