Question

Proteins differ from carbohydrates and lipids in that they always contain nitrogen, carbon, hydrogen, and oxygen.
(A)True
(B)False

Answer 1

Hint: Proteins are very important nutrients in our body and are made of sequences of amino acid molecules. They contain amino and carboxyl groups along with a side chain in their structure.

Complete answer:
The given statement is true. Proteins are different from fats and carbohydrates due to the presence of nitrogen, carbon, hydrogen, and oxygen in them. Carbohydrates only contain carbon, hydrogen, and oxygen whereas fats contain fatty acids which contain a carboxyl group and an alkyl group, thus containing only carbon, oxygen, and hydrogen.

Additional Information:
Protein consists of amino acid chain molecules that contain amine and carboxyl functional groups along with a side chain. The key elements are always carbon, hydrogen, oxygen, and nitrogen. Although the basic molecules are the same, there are 500 naturally occurring amino acids found so far.
Fat, on the other hand, is a chemical makeup of fatty acids which contains a carboxyl group connected to an alkyl group. Therefore, the key elements are carbon, hydrogen, and oxygen.
Carbohydrates consist of carbon, hydrogen, and oxygen and have a generic formula of Cm(H2O)n where m may be different from n. Thus, the hydrogen-oxygen ratio in carbohydrates always remains 2:1.

So, the correct answer to the question is "true".

Note: Proteins are usually polymers of polypeptides formed by sequences of amino acids and are capable of making peptide bonds with other proteins by the loss of one water molecule but the amino acids. These are usually three-dimensional structures and range in size from tens to several thousand amino acids. There are four levels of structure- primary, secondary, tertiary, and quaternary.