Question

What is the reaction in DNA replication catalyzed by DNA ligase?

(a) Addition of new nucleotides to the leading strand

(b) Addition of new nucleotide to the lagging strand

(c) Formation of a phosphodiester bond between the 3’-OH of one Okazaki fragment and the 5’-phosphate of the next on the lagging strand

(d) Base pairing of the template and the newly formed DNA strand

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This interesting question is from DNA Replication in section DNA, RNA and Protein Metabolism of Biochemistry

Answer 1

Correct option is (c) Formation of a phosphodiester bond between the 3’-OH of one Okazaki fragment and the 5’-phosphate of the next on the lagging strand

For explanation: DNA ligase catalyzes the formation of a phosphodiester bond between 3’-OH of one Okazaki fragment and 5’-phosphate of the next.