RNA Structure and Transcription

Question 1

What is the process by which DNA is converted to any form of RNA?

Answer 1

Transcription

Question 2

What are the four major types of RNA?

Answer 2

Messenger RNA, Transfer RNA, Ribosomal RNA, MicroRNA

Question 3

What is the most heterogenous type of RNA in size and base seqeunce composition?

Answer 3

mRNA

Question 4

What form of mRNA carries informatino from >1 gene?

Answer 4

Polycistronic

Question 5

What is the function of the 5’ UTR?

Answer 5

It regulates and directs translation

Question 6

What is the function of 3’ UTR?

Answer 6

Needed for mRNA stability and regulation by mRNA

Question 7

What type of RNA has extensive interchain base pairing that creates a characteristic clover-leaf structure?

Answer 7

tRNA

Question 8

What type of RNA serves as an adaptor molecule to bring a specific amino acid to a growing peptide?

Answer 8

tRNA

Question 9

Where on a tRNA molecule is the amino acid bound?

Answer 9

3’ end

Question 10

What part of the tRNA molecule binds to mRNA?

Answer 10

Anticodon

Question 11

What is the term for catalytically active RNA?

Answer 11

ribozyme

Question 12

How many different sizes of rRNA are in prokaryotes? Eukaryotes?

Answer 12

3; 4

Question 13

What type of RNA is most abundant in the cell?

Answer 13

rRNA

Question 14

To which DNA sequences do RNA polymerases bing?

Answer 14

The promoter

Question 15

In which direction does RNA synthesis occur?

Answer 15

5’–> 3’

Question 16

What molecules serves as the bases in RNA synthesis?

Answer 16

Ribonucleotides

Question 17

What is the relationship of an mRNA transcript to the template strand and coding strand?

Answer 17

Complementary to the template strand and identical to the coding strand

Question 18

How many prokaryotic RNA Polymerases are there?

Answer 18

1

Question 19

How does prokaryotic RNA Polymerase recognize DNA?

Answer 19

Sigma factor

Question 20

Where does the enzymatic activity of RNA Polymerase occur?

Answer 20

In the “core enzyme”

Question 21

What are the stages of transcription

Answer 21

Initiation, Elongation, Termination

Question 22

What consensus sequences are located in the prokaryotic promotor region?

Answer 22

-35 sequence and -10 sequence (Pribnow Box)

Question 23

What enzyme unwinds DNA during transcription?

Answer 23

RNA Polymerase

Question 24

What are abortive transcripts?

Answer 24

Several short pieces of RNA generated in the initation of RNA transcription that ensures the proper location of RNA polymerase

Question 25

At what point is sigma factor released from the core enzyme of RNA polymerase?

Answer 25

Once growing RNA exceeds 10 bases and elongation begins

Question 26

What are the two basic forms of prokaryotic transcription termination?

Answer 26

Rho- independent and dependent termination

Question 27

Which form of prokaryotic transcription termination involves the formation of a hairpin structure?

Answer 27

Rho-independent termination

Question 28

What characteristic of an RNA sequence allows for the formation of a stem-loop structure?

Answer 28

Dyad symmetry

Question 29

What base is found in a series of 8-10 residues in an mRNA transcript utilizing Rho-independent termination?

Answer 29

Uracil

Question 30

What type of prokaryotic transcription termination utilizes energy?

Answer 30

Rho-dependent termination

Question 31

What kind of protein is Rho?

Answer 31

A hexameric adenosine triphosphatase (ATPase) with helicase activity

Question 32

What process is inhibited by Rifampicin?

Answer 32

Transcription Initiation

Question 33

What is Rifampicin's mechanism of action?

Answer 33

Binds to beta subunit of RNA Pol holoenzyme , inbiting the formation of the first phosphodiester bond

Question 34

What process is inhibited by Dactinomycin?

Answer 34

Transcription Elongation

Question 35

What is Dactinomycin's mechanism of action?

Answer 35

Interacts with DNA at the transcriptio initiation complex

Question 36

How many eukaryotic RNA polymerases are there?

Answer 36

3

Question 37

What are the functions of the three eukaryotic RNA Polymerases?

Answer 37

RNA Pol I- transcribes rRNA; RNA Pol II- transcribes mRNA; RNA Pol III- transcribes tRNA and snRNA

Question 38

What consensus sequences are located in the eukaryotic promoter region?

Answer 38

CAAT box (~-70- -80); TATA (Hogness) box (~-25)

Question 39

What allows RNA Pol II to recognize and bind to DNA?

Answer 39

General transcription factors

Question 40

What is the term for any factor, protein, or element that is independent of the promoter or gene being regulated?

Answer 40

Trans-acting element

Question 41

What is the term for any element that is an integral part of the promoter or gene being regulated?

Answer 41

Cis-acting element

Question 42

What is the name of eukaryotic cis-acting non promoter elements that help activate or repress transcription

Answer 42

Enhancers

Question 43

What is the mechanism of activation/ repression by enhancers?

Answer 43

Enhancers bind additional, specific transcription factors and through DNA looping or bending, they then interact with the transcription initiation complex

Question 44

What is the process by which DNA is interconverted from the closed heterochromatic form to the actively transcribed euchromatic forms?

Answer 44

Chromatin Remodeling

Question 45

What is the mechamism of alpha-aminitin?

Answer 45

Binds specifically to RNA Pol II and inhibits its ability to process along the DNA