Question

Peptides are
A. Esters
B. Salts
C. Amides
D. Ketones

Answer 1

Hint: Macromolecules comprise carbohydrates, nucleic acids, proteins, and other significant biomolecules. These polymers are composed of monomers. These monomers are connected by certain bonds.

Complete step by step by answer:
Let's understand the given options in detail.
Option A is ester. Ester is a type of functional group. The structure of the ester functional group is R-CO-OR, where R is for any alkyl group. We know, a peptide is a chain of amino acids. Therefore, option A is wrong.
Option B is salts. A salt is composed of a cation and an anion. And we know that a peptide consists of amino acids. Therefore, option B is wrong.
Option D is ketones. A ketone is a functional group. The formula of a ketone is R-CO-R, where R is for any alkyl group. Therefore, option D is wrong.
 Option C is amides. A chain of amino acids (amides) that is of shorter length is called a peptide. In a peptide, the amino acids are connected by peptide bonds. In a peptide, two to fifty numbers of amino acids are connected by peptide bonds. The structure of peptide bonds is (-CO-NH-)
Hence, option C is right.

Note: Peptides and proteins are differentiated only by their chain length. Peptides are of a shorter chain consisting of two to fifty numbers of amino acids and proteins consist of more than fifty numbers of amino acids. The structure of peptides is not well defined as that of a protein.