RNA primers are necessary in DNA synthesis because
A) DNA polymerase is unable to initiate replication without an origin.
B) the DNA polymerase enzyme requires the 5ʹ (-OH) end of an existing strand to catalyze the addition of deoxyribonucleotides.
C) RNA primase is the first enzyme in the replication complex.
D) primers mark the sites where helicase has to unwind the DNA.
E) the DNA polymerase enzyme requires the 3ʹ (-OH) end of an existing strand to catalyze the addition of deoxyribonucleotides.

Question

Quizplus · Accepted Answer

DNA polymerase requires an existing 3ʹ (-OH) end of a DNA strand to catalyze the addition of deoxyribonucleotides to a new strand. RNA primers provide this necessary 3ʹ (-OH) end to DNA polymerase during replication. Therefore, choice E is the correct option.

RNA Primers Are Necessary in DNA Synthesis Because