DNA Transcription II

Question 1

Where is rRNA synthesized? Where does ribosome assembly begin?

Answer 1

Nucleolus

Question 2

What is rRNA transcribed by?

Answer 2

RNA Polymerase I

Question 3

What regulates the trimming steps of rRNA subunits?

Answer 3

RNAse nuclease, snoRNA

Question 4

*What should we generally know about trimming?

Answer 4

rRNA starts off as a large precursor and ends up as a smaller, mature form of numbered subunits

Question 5

What is the synthesis of subunit 5s RNA regulated by?

Answer 5

RNA Polymerase III

Question 6

Where are ribosomal subunits (40s & 60s) transported to after trimming?

Answer 6

Cytoplasm via nuclear pores

Question 7

What regulates the assembly of GTFs?

Answer 7

RNA Pol I & Pol III

Question 8

What is essential to all cells relative to RNA classes? What does this mean about Pol I & Pol III TFs?

Answer 8

rRNA & tRNA for continued protein synthesis

Pol I and Pol III TFs are stable

Question 9

How do cells regulate specific transcription?

Answer 9

By various levels of control

Question 10

What is needed along with Pol II to begin transcription?

Answer 10

A multitude of GTFs

Question 11

Describe TATA box

Answer 11

Regions of DNA found upstream to highly expressed genes where TATA box protein (TBP) can bind to bend the DNA

Question 12

How do you enhance gene expression for mRNA?

Answer 12

Make GTFs occur more easily. This can happen via “enhancers”

Question 13

How do many factors affect gene expression? What does this do?

Answer 13

They may be needed in combinations to regulate genes. Allows very differentiated cells to fine-tune functions for regulation

Question 14

How can chromatin structures affect transcription

Answer 14

Enhance it by increasing space and allowing polymerase to transcribe more easily

Question 15

What is an example of chromatin modification?

Answer 15

Histone H3 acetylation

Question 16

What does a remodeling complex do?

Answer 16

changes the spacing of chromatin on a histone, allowing for more initiation of gene expression

Question 17

What are the ways that gene regulatory proteins can be regulated themselves?

Answer 17

Protein synthesis
Phosphorylation
Ligand binding
Addition of subunit
Unmasking
Stimulation of nuclear entry
Release from membrane
Generally: THE GENE REGULATORY PROTEINS ARE THEMSELVES REGULATED