Question

3.1.9 - 12.g the molecules in the food we eat contain chemical energy stored in chemical bonds. which statement best explains how this energy is released?
cells burn food molecules, releasing energy as heat that powers movement while keeping the body at the correct temperature.
chemical energy is released as eaten food is digested, giving off heat as a by - product.
cells extract and capture the energy in food molecules all at once, then store it for later use.
chemical bonds in food molecules are broken, releasing energy and allowing cells to use the energy to make atp.

Explanation:

• When food molecules are broken down, the chemical bonds holding them together are broken. This process releases energy.
• Cells use this energy to make ATP (adenosine triphosphate), which is the energy - currency of the cell.
• Option 1: Cells do not "burn" food molecules in the way described. Metabolism is a controlled process, not like burning fuel.
• Option 2: While digestion is part of the process, the key is the breakdown of chemical bonds in cells (not just during digestion) and the production of ATP.
• Option 3: Energy is not extracted all at once. Cellular respiration (a series of steps) is involved in extracting energy from food molecules.

Answer:

Chemical bonds in food molecules are broken, releasing energy and allowing cells to use the energy to make ATP.