Which term describes a chemical used by living things to store and release energy, such as in cellular respiration?

• A. ATP
• B. Acid rain
• C. Biodiversity
• D. Genetic drift

Answer: (A)

The main idea here is that ATP functions as the cell’s energy currency, storing energy in its high-energy phosphate bonds and releasing it when needed. In cellular respiration, energy from nutrients is captured to rebuild ATP from ADP and inorganic phosphate. When a cell needs energy, ATP is hydrolyzed to ADP and Pi, releasing that energy to power processes like muscle movement, transport of substances across membranes, and synthesis of molecules. This system lets cells have a readily available energy source for varied activities.

The other terms don’t describe a molecule that stores and releases energy for cellular work. Acid rain is a pollutant that affects ecosystems, biodiversity refers to the variety of life in an environment, and genetic drift is a random change in allele frequencies over time. None of these describe the cellular mechanism of energy storage and release.