Elements of protein-carbon, hydrogen and oxygen atoms, all proteins have nitrogen and sulfur, phosphorus and other traces of other elements.
Elements of carbohydrates-carbon, hydrogen and oxygen
Elements of fats-carbon, hydrogen and oxygen.
Carbohydrates are used for energy in the form of glucose. Fats are for energy when its broken down to fatty acids. Protein are for repair and growth. It serves as a metabolic fuel source.