Which biomolecule's monomer is an amino acid?

• A. Carbohydrate
• B. Lipid
• C. Nucleic acid
• D. Protein

Answer: (D)

The monomer of a protein is indeed the amino acid. Proteins are large, complex molecules that play many critical roles in the body, and they are constructed from long chains of amino acids. There are 20 different amino acids that combine in various sequences to form proteins, each sequence resulting in a different protein with unique functions and properties.

When amino acids link together through peptide bonds, they form polypeptides. When a polypeptide folds into a specific three-dimensional shape, it becomes a functional protein. This relationship highlights the importance of amino acids as the essential building blocks of proteins.

In contrast, carbohydrates are made up of simple sugars (monosaccharides) as their monomers, lipids are not made of repeating monomers but consist of a variety of components like fatty acids and glycerol, and nucleic acids are polymers made of nucleotide monomers. Each of these biomolecules has a distinct structure and function based on their respective monomers.