Question

Which of the proposed models for the mechanism of initial transcription suggests that the entire RNA polymerase enzyme moves along the DNA? Which of the proposed models is best supported by experimental findings?A. transient-excursion model; scrunching modelB. inch worming model; scrunching modelC. scrunching model; transient-excursion model.D. inchworming model; transient-excursion model

Answer 1

Answer:

The right answer is Letter A

Explanation:

The proposed model for the mechanism of initial transcription that suggests the entire RNA polymerase enzyme moves along the DNA is transient-excursion model, and the proposed model that is best supported by experimental findings is scrunching model.

Because RNA polymerase leaves the promoter, translocate a short way along DNA template, synthesizes a short transcript before aborting transcript, releasing the transcript and returning to its original location on promoter. That is the transient-excursion model.

The scrunching model downstream DNA is pulled into the enzyme and has accumulated within the enzyme as single stranded bulges.

Experiments show that scrunching is right, experiments using single molecule analyses that allow the positions of different parts of polymerase to be measured relative to each other and to the template DNA during transcription.