The two elements which are present in proteins but generally absent in carbohydrates are

Carbohydrates are organic compounds primarily composed of Carbon (C), Hydrogen (H), and Oxygen (O). They generally lack nitrogen and sulphur.

Proteins are polymers of amino acids. Every amino acid contains an amino group (-NH₂), making Nitrogen (N) a fundamental constituent of all proteins. Furthermore, specific amino acids such as cysteine and methionine contain Sulphur (S), which is crucial for forming disulfide bridges that stabilize protein folding. While Carbon and Hydrogen are the building blocks of both carbohydrates and proteins, Nitrogen and Sulphur are the distinguishing elements found in proteins but generally absent in carbohydrates.