Question

Which of the following biomolecules does have a phosphodiester bond?

• A. Nucleic acids in a nucleotide
• B. Amino acids in a polypeptide
• C. Monosaccharides in a polysaccharide
• D. Fatty acids in a diglyceride

Answer 1

The correct option is A

Nucleic acids in a nucleotide

The correct option is A:

Explanation of correct option:

1. One of the structural elements, or building blocks, of DNA and RNA, is the nucleotide.
2. A nucleotide is made up of a base (one of the four substances adenine, thymine, guanine, and cytosine), a sugar molecule, and a phosphoric acid molecule.
3. Between two nucleotides of nucleic acid, a phosphodiester link is created.
4. Between the nucleotides, DNA ligase can produce a phosphodiester bond.
5. It is well known that the phosphodiester bonds serve as the framework for the nucleic acid strands.
6. The phosphodiester bond is known to pre-exist in DNA and RNA at the connection between a sugar molecule's $3$′ carbon atom and a sugar molecule's $5$′ carbon atom, which is deoxyribose in DNA and ribose in RNA.

Explanation of incorrect options:

Option B:

1. A polypeptide is a long chain of amino acids, a protein is made up of one or more polypeptides.
2. And a peptide is made up of two or more amino acids joined together by peptide bonds.

Option C:

1. As a general rule, oligosaccharides have three to ten monosaccharide units while polysaccharides generally have more than ten monosaccharide units.
2. These monosaccharide units are connected by glycosidic bonds.

Option D:

1. An ester bond forms a covalent bond between two fatty acid chains and a glycerol molecule to form a diglyceride.
2. It is also known as diacylglycerol.

Final answer: Nucleic acids in a nucleotide biomolecule have a phosphodiester bond.