DNA Polymerase Catalyzes Phosphodiester Bond Formation

Steps:

• DNA polymerase adds deoxyribonucleotides to the 3' end of a growing DNA strand during replication.
• It links the 3' hydroxyl group of the last nucleotide to the 5' phosphate of the incoming nucleotide.
• This reaction forms a phosphodiester bond, creating the DNA backbone.
• Hydrogen bonds stabilize base pairing but are not enzymatically catalyzed by polymerase.

Why D is correct:

• DNA polymerase catalyzes phosphodiester bonds between the sugar-phosphate backbones of adjacent nucleotides, as defined in DNA replication where dNTPs are polymerized via nucleophilic attack.

Why the others are wrong:

• A: Hydrogen bonds between bases occur spontaneously via base pairing, not enzyme catalysis.
• B: Hydrogen bonds do not link nucleotides; they pair bases within the double helix.
• C: Phosphodiester bonds connect nucleotides, not isolated bases.

Final answer: D