Gene Expression Flashcards

1
Q

What is the 3 stage process involved in making RNA and making a polypeptide?

A

Initiation
Elongation
Termination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens in initiation in transcription?

A

Promoter recognition
Transcription initiation factors
RNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens in elongation in transcription?

A

5’ to 3’ chain growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What happens in termination in transcription?

A

Sequence dependent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the transcription factor recognise on the DNA sequence?

A

TATA box

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens after the TATA box has been recognised?

A
RNA polymerase (promoter) binds over transcription factor 
First building block is produced from the first bases to the left of RNA polymerase - this is where transcription starts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the mRNA transcript made using?

A

Makes complementary strand to DNA template strand

DNA coding strand not used in transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which direction does transcription work in?

A

5’ to 3’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is RNA processing and what does it include?

A

When pre-mRNA is made into mature mRNA

Capping, tailing/polyadenylation, splicing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is capping?

A

Methylated guanine added to 5’ end of sequence in a 5’-5’ linkage
Provides protection and plays role in translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is polyadenylation?

A

Adding a polyA tail to 3’ end of sequence
Uses specific endonuclease to cleave site from RNA polymerase
Uses polyA polymerase to add polyA tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is splicing?

A

Introns are removed from pre-mRNA to leave coding sections which are joined together
Produces mature mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the structure of ribosomes in prokaryotes?

A

3 rRNAs and 56 proteins
30S and 50S subunits
70S ribosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the structure of ribosomes in eukaryotes?

A

4 rRNAs and 82 proteins
40S and 60S subunits
80S ribosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the features of the genetic code

A
Triplet code, degenerate
Non-overlapping
‘Comma-less’ (no gaps)
5’ to 3’ templat read through producing N to C polypeptide chain extension
Adaptor molecule needed, tRNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the initiation triplet?

A

AUG

17
Q

What are the termination triplets?

A

UAA
UAG
UGA

18
Q

tRNA structure formation

A

When two part of a RNA sequence are complementary, hydrogen bonds can form between the anti-parallel complementary sequences forming a loop

19
Q

Where does the amino acid bind to on tRNA?

A

Binds to adenine at 3’ end of sequence

20
Q

What is the anticodon?

A

Section of tRNA (triplet) that is complementary to an mRNA codon

21
Q

What is inosine?

A

Part of anticodon that can bind to any base
5’ base of anticodon and hence 3’ base of codon is wobble position allowing a single tRNA species to recognise more than one codon

22
Q

What happens in the initiation step of translation?

A

AUG codon recognition by methionyl tRNA

Occurs at ribosome

23
Q

What happens in elongation of translation?

A

N to C chain growth

Aminoacyl tRNAs formed

24
Q

What happens in the termination of translation?

A

Stop codons are reached

Translation stops