Food contains organic molecules such as ; energy is released when cells break down this molecule.

The correct answer will be-glucose molecules

Explanation:

The food contains all the molecules which provide the energy to the cell through the process of slow oxidation called cellular respiration.  The respiration provides energy to the cell by breaking down the food particles which provides the substrate like glucose and proteins.

The glucose is used as the major substrate as the cellular respiration breaks down the glucose molecule through glycolysis which is followed by the Citric acid cycle and electron transport chain.

Thus, glucose molecules are the correct answer.