What elements are always present in protein?
A. radium, boron, fluorine, and chlorine
B. mercury, iron, lead, and aluminum
C. carbon, hydrogen, oxygen, and nitrogen ( ✔ )
D. neon, argon, krypton, and copper
<h2><u>Explanation</u> : </h2>
Proteins are one of the primary constituents of living matter. They consist of long chains of amino acids, which are bonded together by peptide linkages and thus called polypeptides. There are about 20 amino acids, and the atoms most prevalent in these are carbon, hydrogen, oxygen, nitrogen, and sulphur.
