The energy we obtain from food comes mainly from the organic molecular bonds within proteins, carbohydrates, and lipids. Our digestive enzymes break these bonds (catabolism) so that we can have small molecules like simple sugars (glucose), amino acids, and fatty acids (triglycerides). These small molecules can enter cells where their remaining C-C (carbon-to-carbon bonds) are broken, which releases energy captured in cellular molecules in order to generate Adenosine Tri-Phosphate (ATP). ATP is universal for every cell in your body to use as an instant energy source or "snack."
