During elongation, RNA polymerase has three prominent channels, or grooves. These channels provide sites for all of the following EXCEPT ________.
A) a site for the double-stranded DNA molecule
B) a site for the entry of ribonucleoside triphosphates
C) a site for the exit of the diphosphates removed from the nucleotide triphosphates
D) a site for the growing RNA strand

Question

Quizplus · Accepted Answer

During elongation, RNA polymerase indeed has channels for the double-stranded DNA molecule, the entry of ribonucleoside triphosphates, and the growing RNA strand. However, it does not specifically have a channel for the exit of diphosphates removed from the nucleotide triphosphates; these are typically released into the surrounding environment without a dedicated exit channel.

During Elongation, RNA Polymerase Has Three Prominent Channels, or Grooves