Chapter 3.3

Question 1

Give 5 differences between RNA and DNA

Answer 1

The sugar in RNA is ribose while that in DNA is deoxyribose
The base uracil in RNA replaces thymine in DNA
While the 5’ end of DNA strand is typically a mono phosphate, the 5’ end of an RNA molecule is a triphosphate
RNA molecules are usually much shorter than DNA molecules
RNA molecules are single stranded while DNA molecules are double stranded

Question 2

RNA molecules have properties of both DNA and

Answer 2

Proteins

Question 3

The hypothesis that the earliest organisms relied on RNA for both catalysis and information storage is known as

Answer 3

RNA world hypothesis

Question 4

The enzyme that carries out the polymerization of ribonucleoside triphosphates is

Answer 4

RNA polymerase

Question 5

The RNA polymerase acts by adding successive nucleotides to the …….’ End of the growing transcript

Answer 5

3’

Question 6

Which strand of the DNA is transcribed?

Answer 6

The template or non coding strand

Question 7

What happens in the first stage of transcription

Answer 7

During initiation,
RNA polymerase and other protein are attracted to the double-stranded DNA
The DNA strands are separated and transcription of the template strand actually begins

Question 8

In transcription, the process by which successive nucleotides are added to the 3’ end of the growing RNA transcript as the RNA polymerase proceeds along the template strand is

Answer 8

Elongation

Question 9

What happens during termination in transcription

Answer 9

RNA polymerase stops transcribing and the transcript is released and this occurs when RNA polymerase encounters a sequence in the DNA template called a terminator

Question 10

Transcription starts at. …………. and ends at a ………

Answer 10

Promoter
Terminator

Question 11

A regulatory region where RNA polymerase and associated proteins bind to the DNA duplex is

Answer 11

Promoters

Question 12

The DNA sequence in many promoters in eukaryotes and archaeons that serves as a protein binding site for a key general transcription factor is

Answer 12

TATA box

Question 13

In bacteria, promoter recognition is mediated by a protein called

Answer 13

Sigma factor

Question 14

A set of proteins that bind to the promoter of a gene whose combined action is necessary for transcription is

Answer 14

General transcription factors

Question 15

A protein that binds to a sequence in DNA to enable transcription to begin is

Answer 15

Transcriptional activator protein

Question 16

The transcriptional activator protein binds to a specific DNA sequence known as

Answer 16

Enhancer

Question 17

What is the purpose of transcriptional activator protein

Answer 17

They help to control when and in which cell transcription of a gene will occur

Question 18

A complex of proteins that interacts with the Pol II complex and allows transcription to begin is known as

Answer 18

Mediator complex

Question 19

The RNA polymerase complex responsible for transcription of protein-coding genes is

Answer 19

Pol II