What do cells store and release as the main source of chemical energy?

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

Answer: (C)

Verified step by step guidance

1. Understand the role of ATP in cellular processes: ATP, or adenosine triphosphate, is the primary energy carrier in cells. It stores energy in its high-energy phosphate bonds and releases it when these bonds are broken.
2. Recognize the structure of ATP: ATP consists of an adenine base, a ribose sugar, and three phosphate groups. The energy is stored in the bonds between the phosphate groups.
3. Learn how ATP releases energy: When a cell needs energy, ATP undergoes hydrolysis, breaking the bond between the second and third phosphate groups, forming ADP (adenosine diphosphate) and an inorganic phosphate (Pi). This reaction releases energy that the cell can use for various functions.
4. Compare ATP with other molecules: While NADH, FADH2, and glucose are involved in energy processes, ATP is the immediate source of energy for cellular activities. NADH and FADH2 are electron carriers used in the electron transport chain, and glucose is a primary fuel for cellular respiration.
5. Explore the regeneration of ATP: Cells regenerate ATP from ADP and Pi through processes like cellular respiration and photosynthesis, ensuring a continuous supply of energy for cellular activities.