Which statement best characterizes the role of ATP in cellular metabolism?

• A. ATP functions mainly as an enzyme that catalyzes metabolic reactions.
• B. ATP is a storage form of genetic information.
• C. ATP acts as the primary energy currency, coupling exergonic and endergonic reactions.
• D. ATP serves as a structural component of cell membranes.

Answer: (C)

Verified step by step guidance

1. Understand the role of ATP in cellular metabolism: ATP (adenosine triphosphate) is a molecule that stores and transfers energy within cells. It is not an enzyme, genetic material, or a structural component of membranes.
2. Recognize the concept of energy coupling: ATP acts as the primary energy currency in cells, linking exergonic reactions (energy-releasing) to endergonic reactions (energy-consuming). This allows cells to perform work efficiently.
3. Learn the structure of ATP: ATP consists of an adenine base, a ribose sugar, and three phosphate groups. The bonds between the phosphate groups are high-energy bonds, and breaking these bonds releases energy.
4. Understand how ATP is used: When ATP is hydrolyzed (broken down) into ADP (adenosine diphosphate) and inorganic phosphate (Pi), energy is released. This energy is then used to drive various cellular processes, such as muscle contraction, active transport, and biosynthesis.
5. Review why the correct answer is 'ATP acts as the primary energy currency': This statement accurately describes ATP's role in cellular metabolism, as it facilitates the transfer of energy between reactions, enabling the cell to maintain its functions and homeostasis.