The breakdown of chemical bonds releases energy. If you were to measure the amount of energy from a candy bar, you would see that it might have 200 calories or more. While the body needs energy to function, the immediate release of chemical energy from the breakdown of food and nutrients would be disaterous. It is the work of enzymes that allow for the controlled release of the energy in living chemical reactions. Plants turn the energy of sunlight directly into food by tying sunlight energy into chemical bonds in the form of sugar.
Enzymes are responsible here, too, they control the absorption of radiant energy.
The sunshine will be hot enough to melt tar on the streets, but plant leaves remain bearly warm to the touch. It is slowly being tied up in the chemical bonds of sugar. The process is photosynthesis and it is the basis of all life on earth, but without enzymes controls this process would be impossible. Enzymes are at work wherever there is life. Yeast use enzymes to levin bread and ferment sugar into alcohol.