Video Transcript
Which of the following statements about RNA polymerase is correct? (A) RNA polymerase catalyzes the breaking of phosphodiester bonds. (B) RNA polymerase binds to DNA at a specific start codon, which is complementary to
the polymerase’s anticodon site. (C) RNA polymerase forms a strand of complementary DNA by catalyzing the formation of
hydrogen bonds. (D) RNA polymerase creates an RNA strand from five prime to three prime using the
three prime to five prime DNA strand as a template. (E) RNA polymerase remains stationary while transcription occurs along a strand of
DNA.
What is RNA polymerase? What function does it serve in the human cell? RNA polymerase is involved in transcription. Transcription is the process of converting DNA into mRNA, which can then be
translated into protein. During transcription, RNA polymerase unwinds double-stranded DNA and uses one of the
strands as a template for creating a single strand of mRNA. RNA polymerase moves along the molecule of DNA as it synthesizes mRNA, so answer
choice (E) is incorrect.
RNA polymerase forms a strand of mRNA and not complementary DNA, so answer choice (C)
is incorrect. We can also eliminate answer (A). Phosphodiester bonds make up the backbone of both DNA and RNA to join nucleotides
together. RNA polymerase makes phosphodiester bonds in mRNA and doesn’t break them. Answer choice (B) is also incorrect as this is describing steps in translation, which
doesn’t involve RNA polymerase but involves the ribosome instead.
The only correct statement is that RNA polymerase makes an mRNA strand in the five
prime to three prime direction using the opposing three prime to five prime DNA
strand as a template. Therefore, answer choice (D) is correct. RNA polymerase creates an RNA strand from five prime to three prime using the three
prime to five prime DNA strand as a template.
