1 During prokaryotic transcription the strand is read by i

1) During prokaryotic transcription, the _________ strand is read by ___________ in the __________ direction while the ________ is made in the ___________ direction.

A) coding, RNA polymerase, 5’ to 3’, RNA, 3’ to 5’.

B) coding, RNA polymerase, 3’ to 5’, RNA, 5’ to 3’.

C) template, DNA polymerase III, 5’ to 3’, leading strand, 3’ to 5’.

D) template, DNA polymerase III, 3’ to 5’, leading strand, 5’ to 3’.

E) template, RNA polymerase, 3’ to 5’, RNA, 5’ to 3’.

Solution

During prokaryotic transcription, the RNA polymerase binds to the promoter region of the DNA double strand, which lies directly upstream of the sequence to be transcribed. The DNA double strand unwinds, exposing 12-17 bases. Synthesis of the RNA molecule begins by adding ribonucleotides complementary to the unwound DNA template. The DNA continually unwinds and rewinds as transcription occurs. The template DNA strand is read in the 3\' to 5\' direction, while the RNA molecule is synthesized in the 5\' to 3\' direction. Termination of transcription signals rewinding of exposed DNA as well as dissociation of RNA polymerase molecule and newly synthesized RNA molecule. The RNA may be post-transcriptionally modified before being transported to ribosome 70S or other organelles for translation into protein molecule.

Thus, the correct answer is E) template, RNA polymerase, 3\' to 5\', RNA, 5\' to 3\'