Question

During transcription, in what direction is (1) RNA synthesized and (2) the DNA template "read"?a. (1) 5'→3'; (2) 3'→5'b. (1) 5'→;3' (2) 5'→;3'c. (1) 3'→;5'; (2) 3'→5'd. (1) 3'→5'; (2) 5'→3'

Answer 1

The correct answer is: a. (1) 5'→3'; (2) 3'→5'

In nucleic acids (DNA and RNA) 5’ end refers to phosphate group attached to the 5′ carbon of the ribose ring, while 3’ end refers to the ribose -OH substituent. Nucleic acids can only be synthesized in the 5′-to-3′ direction, which means that the DNA template is read in 3’—5’. Translation of the protein by the ribosome will also proceed in a 5′ to 3′ direction, which means that the mRNA template is 3’—5’.