Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FLC > Protein Synthesis > Flashcards

Protein Synthesis Flashcards

1
Q

Explain the flow of genetic info

A

Transcription -> Pre mRNA -> Capping / PolyA tail / Splicing -> Mature mRNA

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

How does the cell know when to undergo translation?

A

mRNA is exported out the nucleus and recognised by the ribosome for translation

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

Describe the structure of eukaryotic mRNA

A 
5' capped end 
followed by 5' UTR 
Coding region in the middle 
3' UTR 
3' polyAdenylated tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the consequences of mRNA modification errors?

A

Protein is unable to leave the cell and is degraded

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

What does the coding region consist of?

A

Exons

including the initiaton codon

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

What is the initiation codon?

A

AUG methionine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many bases are read at a time by the ribosome?

A

3 bases / 1 codon

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

How are the amino acids assembled at the ribosome?

A

Complementary anitcodon to mRNA codon on tRNA
Amino acids on 3’ end of tRNA
form peptide bonds

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

What is the role of the 5’ UTR?

A

Determines rate of protein synthesis

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

What is the significance of the 3’ UTR ?

A

Affects stability

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

Explain what it means when we describe the genetic code as universal?

A

More than one codon can code for the same amino acid

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

Describe the consequences of a transcription / translation error

A

Unable to fold protein correctly, structure changes = non functional

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

What are ribosomes composed of?

A

rRNA and ribonucleoprotein complexes (protein)

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

What are the 2 types of ribosome?

A
  • ribosomes free in cytosol

- ribosomes bound to ER

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

Where does protein synthesis occur?

A

At a cleft between a large and small ribosomal subunit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

At what rate does a ribosome add amino acids to form a

protein?

A

20 amino acids per second

17
Q

Why are so many ribosomes required?

A

To maintain high speed of translation to fulfill cells needs

18
Q

List the different types of RNA and their approximate % cellular abundance

A

rRNA : 80-85%
tRNA: 10-15%
mRNA: 2-5%

19
Q

Which size ribosomal subunits do mamallian ribosomes consist of?

A

40s (small) and 60s (large)

20
Q

Collectively what size are mamallian ribosomes?

A

80s

21
Q

What are the 3 stages of translation?

A
  1. Initiation
  2. Elongation
  3. Termination
22
Q

Describe in detail what occurs during Initiation of translation?

A
  1. mRNA in cytoplasm
  2. EiF1 and Eif3 bind to 40s subunit, separating it from 60s
  3. EiF2 binds to tRNA
  4. 40s binds to tRNA
  5. EiF1,2, and 3 form 48 pre initiation complex
  6. EiF4 binds to 5’ cap
  7. Complex scans for AUG start codon
  8. 60s joins 40s at start codon
  9. All EiF’s are released
23
Q

Does protein synthesis require energy?

A

YES, it is energetically expensive

24
Q

How much energy is consumed during inititation?

A

2 GTP molecules and nATP

25
Q

Outline the Elongation process of translation

A
  1. Initiator tRNA in P site
  2. Complementary anticodon in A site
  3. Due to close proximity of amino acids, peptide bonds form
  4. Ribosome moves 1 codon along
  5. Empty/used tRNA moves to E site and is released
  6. Other tRNA (prev. in A site) moves to P site and holds chain
  7. => peptidyl RNA
26
Q

How much energy does elongation of the polypeptide require?

A

2 GTP molecules and amino acids

27
Q

How does Termination of translation occur?

A
  1. UAG stop codon in A site
  2. No complementary anticodon to UAG stop codon
  3. Release factor recognises stop codon
  4. Hydrolysis of terminal peptidyl tRNA
  5. Polypeptide released
28
Q

How much energy is required to charge tRNA molecules with amino acids?

A

1 ATP molecule each and amino acids

29
Q

What energy is used in termination of translation?

A

1 GTP molecule

30
Q

What is the size of prokaryotic ribosomes?

A

70s ribosomes

- 50s and 30s subunits

31
Q

Compare the differences in ribosomes between prokaryotes and eukaryotes

A

Prokaryotic

  • 23 and 5s large RNA subunits
  • 31 large subunit proteins
  • 16s small RNA subunits
  • 21 small subunit proteins

Eukaryotic

  • 28, 5.8 and 5s large RNA subunits
  • 49 large subunit proteins
  • 18s small RNA subunits
  • 33 small subunit proteins
32
Q

How can the difference in ribosomes between prokaryotes and eukaryotes be beneficial to us?

A

Can use antibiotics to inhibit protein synthesis in bacterial ribosomes ONLY, to prevent disease

33
Q

Give an example of an antibiotic that targets bacterial protein synthesis

A

Streptomycin - inhibits initiation process in protien synthesis

FLC (34 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions