Session 8-Gene Expression Flashcards Preview

Semester 1-MCBG > Session 8-Gene Expression > Flashcards

Flashcards in Session 8-Gene Expression Deck (29):
1

What three things does the process of making a polynucleotide or polypeptide need?

Enzyme
Activated substrates
Template

2

What is the:
Enzyme?
Activated substrate?
Template?
For DNA?

DNA polymerase
dNTPs
DNA

3

What are the names of the three stages in making a polynucleotide or polypeptide?

Initiation
Elongation
Termination

4

What is the:
Enzyme?
Activated substrate?
Template?
For making RNA?

RNA polymerase
NTPs
DNA

5

What is the process of making RNA called?

Transcription

6

What is the:
Enzyme?
Activate substrate?
Template?
For making a polypeptide?

Ribosome
AA
mRNA

7

In transcription, what is involved in the initiation stage? (3)

Promoter recognition
Transcription initiation factors
RNA polymerase

8

Why is a TATA box important?

Transcription factor binding to a TATA box sets the direction of transcription

9

What happens in elongation in transcription?

5' to 3' chain growth

10

Which two methods protect mRNA against degradation?

Capping
Tailing or polyadenylation

11

What happens in capping?

A 5' to 5' linkage is created to provide protection against degradation

12

What happens in tailing or polyadenylation?

Occurs at the 3' end of the chain (polyA tail)

13

Why are there methods to prevent mRNA degradation?

Because RNA is unstable and is always degrading so it needs to be controlled

14

What is splicing?

Occurs in the middle of the mRNA strand and involves the removal of introns and is sequence dependent

15

What are the 5 different types of RNA?

rRNA
mRNA
tRNA
miRNA
Noncoding RNA

16

Which RNA polymerase is used to make rRNA?

RNA polymerase I

17

Which RNA polymerase is used to make mRNA?

RNA polymerase II

18

Which RNA polymerase is used to make tRNA?

RNA polymerase III

19

True or false: every transcription starts with AUG codon so every protein starts with methionine

TRUE

20

What are the three termination codons?

UAA
UAG
UGA

21

What is inosine?

Base in tRNA anticodons which can read U, C and A in the 3rd position

22

What is a wobble base?

Wobble base pairs do not follow the normal base pair rules:
G-U
I-U
I-A
I-C

23

What happens in initiation of translation?

AUG codon recognition
Special methionyl tRNA
Ribosome

24

What happens in elongation in translation?

N to C chain growths
Aminoacyl tRNAs - A site is the point of entry for aminoacyl tRNA (except for first aminoacyl tRNA which enters at P site)
P site is where peptidyl tRNA is formed in ribosome

25

What is aminoacyl tRNA?

tRNA to which AA is chemically bonded and delivers AA to ribosome for incorporation into polypeptide chain that is being produced

26

What happens in termination of translation?

Stop codons are identified

27

What are the subunits found in eukaryotic ribosomes?

40S and 60S subunits, which make up 80S

28

What are the subunits found in prokaryotic ribosomes?

50S and 30S which make up a 70S ribosome

29

What is a TATA box?

DNA sequence that indicates where a genetic sequence is read and decoded. It is a type of promoter sequence, which specifies to other molecules where transcription begins