Weak covalent bonds, such as ones in carbohydrates and lipids, have:

Weak covalent bonds such as the ones in carbohydrates and lipid have A LOT OF POTENTIAL ENERGY. 
Potential energy refers to energy stored in a substance. The potential energy in the covalent bond of macro molecules are converted to chemical energy in food, the chemical energy is used by the body system to carry out all the biochemical reactions that will keep the cells alive.

The answer is reflection.