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Flashcards in Kandpal - Transcription Deck (34):
1

What are the structural differences between RNA and DNA?

RNA is mostly single stranded, ribose, uracil
DNA is double stranded, deoxyribose, thymine

2

List the different RNAs from least abundant to most.

mRNA, tRNA, and rRNA

3

List 4 functions of RNA.

Genome, information carrier, protein synthesis, and as a catalyst.

4

What is an example of RNA as a genome?

HIV virus

5

How is RNA involved in protein synthesis?

As rRNA and tRNA

6

Name an example of a catalytic RNA.

peptidyl transferase

7

What carbon is different between ribose and deoxyribose?

2' carbon

8

Where is mRNA located?

nucleus and cytoplasm

9

Where is tRNA located?

cytoplasm

10

Where is rRNA located?

ribozymes and nucleus

11

How many subunits does RNA polymerase in E. coli have?

5 subunits

12

What part of the RNA polymerase recognizes the promoter sequence?

the sigma subunit recognizes the promoter sequence

13

What does tight binding of the promoter with the promoter sequence lead to?

opening of the DNA

14

What is strength of binding and speed of binding dependent on?

It is dependent on the promoter sequence

15

What occurs if the promoter sequence is closely related to the sigma subunit?

The bond forms faster and it is a stronger/tighter bond

16

What are known as consensus sequences?

the short conserved sequences of the promoter sequence

17

What is the -35 consensus sequence?

35 bases upstream of the start site; varies from 16-19 base pairs

18

What is the -10 consensus sequence?

10 bases upstream of the start point; varies from 5-9 base pairs

19

What is the starting point referred to?

+1

20

How many RNA polymerases do eukaryotes have and how many do bacteria have?

Eukaryotes have 3 and bacteria only has one.

21

How does eukaryotic RNA polymerase bind to promoter?

Binds indirectly by contacting promoter sequences via transcription factors

22

Between eukaryotes and bacteria which uses operons?

bacteria

23

Which genes are individually regulated bacteria or eukaryotic?

Eukaryotic

24

Which bacterial polymerase directly binds the promoter sequence?

the bacterial RNA polymerase holoenzyme that contains the sigma subunit

25

How can bacterial and eukaryotic RNA polymerases be distinguished?

By their susceptibilities to two inhibitors: rifampin (bacterial) and alpha-amanitin (eukaryotic)

26

How does rifampin inhibit bacterial RNA polymerase?

it binds to the beta subunit and blocks the path of nascent RNA

27

How does alpha-amanitin inhibit eukaryotic RNA polymerase?

binds to and inactivates the largest subunit of RNA polymerase II, RPB1

28

What blocks transcription in both bacterial and eukaryotic polymerases?

actinomycin-D prevents transcription in both by binding to DNA

29

What kind of antibiotic is Rifampicin?

broad-spectrum antibiotic used for mycobacterial infections (pts w/TB and immunosuppressed pts)

30

What is a point of concern with rifampicin antibiotics?

point mutation in bacterial beta subunit changes rifampin binding site and does not allow it to bind

31

What type of antibiotic is Ciprofloxacin?

A quinolone antibiotic

32

How does quinolone work?

binds to the A subunit of bacterial DNA gyrase and impairs DNA cleavage and resealing activity = DNA damage

33

What type of antibiotic is Novobiocin?

A coumarin antibiotic

34

How does Novobiocin work?

inhibits bacterial DNA gyrase by binding to the ATP binding site of the B subunit = inhibition DNA supercoiling (transcription of genes is disrupted)