Question

which four elements are found in every protein? some proteins contain additional elements. carbon phosphorus sulfur nitrogen hydrogen oxygen

Explanation:

Proteins are macromolecules made up of amino - acid monomers. The basic structure of amino acids contains carbon, hydrogen, oxygen, and nitrogen atoms. These four elements are present in every protein. Sulfur is present in some amino acids like cysteine and methionine, and phosphorus is not a part of the basic structure of all proteins.

Answer:

carbon, hydrogen, oxygen, nitrogen