Reading 5

Question 1

What is transcription?

Answer 1

Process of the information in a strand of DNA being copied into a new molecule of mRNA (DNA copied to RNA)

Question 2

3 major classes of RNA in prokaryotic and eukaryotic cells? What is the function of each?

Answer 2

-Messenger RNA (mRNA): provides template for protein synthesis
-Transfer RNA (tRNA): brings amino acids and reads genetic code
-Ribosomal RNA (rRNA): structural and catalytic role

Question 3

What is the nucleotide substrate for RNA polymerase?

Answer 3

Ribonucleoside triphosphates

Question 4

How do ribonucleotides, deoxyribonucleotides, and dideoxyribonucleotides differ?

Answer 4

Ribonucleotide: nucleotide with ribose as pentose component, unit for amino acid
Deoxyribonucleotide: contains deoxyribose , unit for DNA
Dideoxyribonucleotides: stop chain elongation

Question 5

What are the three main steps of transcription in bacteria?

Answer 5

Initiation, elongation, and termination

Question 6

What does the enzyme RNA polymerase do?

Answer 6

Copies DNA sequence into RNA using a DNA template

Question 7

What is sigma factor, and what does it do?

Answer 7

A protein needed for the initiation of transcription in bacteria

Question 8

Define the term polycistronic RNA?

Answer 8

A mRNA that encodes many proteins which work to aid in transcription

Question 9

Eukaryotes have many types of RNA polymerases. How do they differ from each other?

Answer 9

there’s 3 and they all transcribe different RNA genes

Question 10

What is a promoter, and what does it do?

Answer 10

A region of DNA where proteins bind to initiate transcription of that gene

Question 11

What is a transcription bubble?

Answer 11

A molecular structure formed during DNA transcription when a limited portion of DNA double helix is unwound

Question 12

12. Draw a schematic of a general bacterial promoter, clearly labeling the -10, and -35 regions, and +1 start site.

Answer 12

promoter circle in middle withe line across
on line there are 2 spaces -35 on left and -10 on right
to the right of the circle still on the line is the +1 start site

Question 13

What is the significance of the +1 position at the bacterial promoter?

Answer 13

Its where transcription starts

Question 14

What are the components of the bacterial holoenzyme transcriptional complex?

Answer 14

35 element, extended -10 element, -10 element, discriminator