Identify the elemental makeup of proteins.

Carbon, Hydrogen, and Oxygen

Carbon, Hydrogen, and Oxygen in a 1:2:1 ratio

Carbon, Hydrogen, Oxygen, and Nitrogen

Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus

Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus

Explanation:

Proteins are mainly made up of amino acids. The basic structure of amino acids is that they have a carboxylic group, amino group and side chain. The carboxylic group is mainly Carbon, Hydrogen and Oxygen. The amino group is mainly Nitrogen and Hydrogen. The side chains are unique per amino acid having different elements including Phosphorus.