Which of the following illustrates energy coupling in metabolism?

• A. Energy coupling is the process by which energy released from exergonic reactions powers endergonic processes, such as ATP hydrolysis powering active transport.
• B. Energy coupling is the process by which energy stored as heat powers all cellular work.
• C. Energy coupling is the spontaneous conversion of CO2 into glucose without energy input.
• D. Energy coupling occurs only in photosynthesis and nowhere else.

Answer: (A)