Questions: Which description properly describes a step involved in cellular respiration? (3 points) Glucose is broken apart, then the energy gained is transferred to the energy molecule. Carbon dioxide is combined with oxygen to make glucose. Water is divided into carbon dioxide and glucose. Oxygen is combined with the energy molecule to energize it.

The answer is the first one: Glucose is broken apart, then the energy gained is transferred to the energy molecule.

Explanation for each option:

1. Glucose is broken apart, then the energy gained is transferred to the energy molecule.

   • This option correctly describes a step in cellular respiration. During glycolysis and the citric acid cycle, glucose is broken down, and the energy released is used to form ATP, the energy molecule.

2. Carbon dioxide is combined with oxygen to make glucose.

   • This option describes a process that occurs in photosynthesis, not cellular respiration. In photosynthesis, carbon dioxide and water are used to produce glucose and oxygen.

3. Water is divided into carbon dioxide and glucose.

   • This option is incorrect. Water is not divided into carbon dioxide and glucose in cellular respiration. Instead, water is a byproduct of the electron transport chain in cellular respiration.

4. Oxygen is combined with the energy molecule to energize it.

   • This option is incorrect. Oxygen is the final electron acceptor in the electron transport chain, where it combines with electrons and protons to form water, but it does not directly combine with ATP to energize it.

In summary, the correct description of a step involved in cellular respiration is the breakdown of glucose and the transfer of energy to ATP.