What Proteins Are Made of Proteins contain carbon, hydrogen, oxygen, and __________ atoms. The building blocks of protein are called

Answer

The first blank should be filled with 'nitrogen'. Proteins are organic macromolecules composed mainly of four elements: carbon (C), hydrogen (H), oxygen (O), and nitrogen (N). Some proteins also contain sulfur (S). The presence of nitrogen is a distinguishing feature of proteins compared to carbohydrates and lipids. The second part of the question asks for the building blocks of protein, which are 'amino acids'. Amino acids are the monomer units that link together through peptide bonds to form long chains called polypeptides, which then fold into functional proteins. Therefore, the completed sentences are: 'Proteins contain carbon, hydrogen, oxygen, and nitrogen atoms. The building blocks of protein are called amino acids.'