How does ATP participate in energy-coupling reactions?

• A. Hydrolysis of ATP fuels endergonic reactions.
• B. Hydrolysis of ADP fuels endergonic reactions.
• C. Synthesis of ATP fuels exergonic reactions.
• D. Synthesis of ADP fuels exergonic reactions.

Answer: (A)

Verified step by step guidance

1. Understand the concept of energy-coupling: In biological systems, energy-coupling refers to the process where energy released from an exergonic reaction is used to drive an endergonic reaction.
2. Learn about ATP (adenosine triphosphate): ATP is a molecule that carries energy within cells. It is composed of adenine, ribose, and three phosphate groups.
3. Explore ATP hydrolysis: Hydrolysis of ATP involves breaking the bond between the second and third phosphate groups, releasing energy. This reaction is exergonic, meaning it releases energy.
4. Connect ATP hydrolysis to endergonic reactions: The energy released from ATP hydrolysis can be used to drive endergonic reactions, which require an input of energy to proceed.
5. Consider the synthesis of ATP: The synthesis of ATP from ADP (adenosine diphosphate) and inorganic phosphate is an endergonic process, requiring energy input, often from cellular respiration or photosynthesis.