Question

Which enzyme catalyses the synthesis of a new strand for a DNA molecule by linking nucleotides to the developing strand?

Options

• DNA ligase

• DNA polymerase

• Single-strand binding proteins

• Topoisomerase

Answer 1

DNA polymerase

Explanation:

DNA polymerase is the enzyme that adds deoxyribonucleotide triphosphates to the 3′-OH end of a growing DNA strand, synthesising the new strand in the 5′→3′ direction. DNA ligase instead seals nicks and joins Okazaki fragments after synthesis.