What do elephants use for energy

Sixteen to eighteen hours or nearly 80% of an elephant's day is spent feeding. Elephants consume grasses, small plants, bushes, fruit, twigs, tree bark, and roots. Tree bark is a favorite food source for elephants. It contains calcium and roughage, which aids digestion.

Explanation:

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme