Chemically alter the make-up of nutrients, changing them into a form that can be readily used by cells.
a. enzymes
b. amino acids
c. carbohydrates
d. nutrients

Enzymes breaks down the food into digestibale forms. peptidases and proteases break down proteins, lipases break fats into glycerol and fatty acids, amylases break down carbohydrates into simpler utilizable sugars like glucose etc. Nucleases break down nucleic acids into nucleotides.