What happens to macromolecules from food during digestion?

They are broken down into smaller molecules and are made into ATP (cellular respiration), or into storage fat for the body's reserve energy. They are broken down in a process called hydrolysis.

During carbohydrate digestion the bonds between glucose molecules are broken by salivary and pancreatic amylase. The digestion of certain fats begins in the mouth, where short-chain lipids break down into diglycerides because of lingual lipase.