ANSWER: A living organism intakes food, it breaks down into mostly water and large organic molecules. These large organic molecules are Fat, Proteins, Glucose, Starch and Cellulose. These molecules are still not usable by the cells so the body breaks these large polymers into small monomers.
In cow's muscles, protein muscles are built by tapping 4 amino acid monomers. Fat muscles are built by tapping 3 fatty acid monomers and 1 glycerol molecule.
Cows use glucose molecules to mix with oxygen to release chemical energy in cellular respiration. Cows can make fat molecules and glucose molecules because fatty acids and glycerols are made up of same atoms, C, H and O.