Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MAT209 > Translation (RNA--> Protein) > Flashcards

Translation (RNA--> Protein) Flashcards

(49 cards)

Start Studying
1
Q

Transcription

A

converting DNA–> RNA

The moving of information that is encoding in the DNA –> RNA

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

Why is is called transcription

A

Language (monomers) between DNA and RNA is the same. They are both made out of nucleotides (they are poly nucleotides)

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

Translation

A

Language between RNA and Proteins are different. The monomers that the proteins are made of change. Proteins are made of amino acids whereas in RNA it is nucleotides

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

What does the genetic code do

A

It explains how nucleotide sequenced become amino acid sequences

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

How many nucleotides come together to form an amino acid?

A

3 nucleotides code for 1
amino acid
We call each of these nucleotides codons

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

How many possible RNA nucleotides are there?

A

4 Possible

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

How many nucleotide combinations are there

A

64 combinations forming aminos acids

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

How many amino acids are there

A

20

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

Why are there 64 codon combinations but only 20 amino acids. Why?

A

Redundancy in code.

Some amino acids are specified by more than one triplet. Many codons can code for the same amino acid

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

Amino acid code from RNA is universal for…

A

All present day organisms except for mitochondria who have their own transcription and translation mechanisms.

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

Is mRNA single or double stranded

A

Single

long strand of nucleotides

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

What is a reading frame

A

This considers where you start counting your nucleotides from
Each mRNA has three different reading frames
Deciding this depends on the starting codon.

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

Transfer RNA

A

tRNA

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

Messenger RNA

A

mRNA

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

Ribosonal RNA

A

rRNA

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

What is tRNA

A

A long strand of nucleotides.
Because complementary strands of nucleotides can hydrogen bond they are able to form secondary and tertiary structures.
tRNA forms a clover leaf shape. This has two important sections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the two important sections of the clover shaped secondary tRNA structure

A

Anti Codon -3 letter code that is complementary to the codon that is present in the mRNA. It recognisses the codons on the mRNA

3 prime end of the tRNA. This is where it attaches to the amino acid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How many nucleotides normally form a tRNA

A

80

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Further folding of the clover shape and Hydrogen bonding can cause what shape to form

A

L Shape
Final shape
Tertiary structure- always exists in this structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Wobble (base) pairing

Study These Flashcards
A

Looks at the redundancy in the code.
The nature of the nucleotides that creates tRNA is that the variations in the codons that create an amino acid tend to be in the last of the three codons
The idea of wobble pairing means that the tRNA can recognise flexibility

21
Q

Why is there wobble pairing

Study These Flashcards
A

Gives the cells conservation of resources and energy so it does not produce all 60 tRNAs

22
Q

How are tRNAs manufactured inside the cell?

Study These Flashcards
A

The enzyme- aminoacyl-tRNA synthetases

The enzyme bashing the amino acid and tRNA together
It brings them close together so there is a high energy bond that is formed.
It is an active process which means energy is expended in the process so one atp is consumed

23
Q

Ribosome

Study These Flashcards
A

A complex that is made of both proteins and rRNA.

24
Q

What does mRNA do.

Study These Flashcards
A

mRNA+tRNA+ Ribosomes
the mRNA brings the mRNA in close proximity with the tRNA and catalyses the whole process of forming a polynucleotide

Basically a Catalyst

25
What is the function of a ribosome
Peptidle transferase produces a polypeptide ribosomes create polypeptides Bring together the mRNA and tRNA. As it builds the polypeptide chain it moves along the mRNA (like a little machine) one codon at a time.
26
What is the structure of a ribosome
The actual structure is unknown - Finer details We know it is made up of one large subunit and one small Each of the subunits are made of proteins as well as RNA They are several million daltons in size (large subunit- can be seen under electron microscopes) Quaternary structure
27
What are the three important sights in the ribosomes
The A site The P site The E site - the eject site
28
What is the function of the small subunit in a ribsome
Contains mRNA binding site and links to the tRNAs
29
What is the function of the large subunit in a ribosome
Catalyses the formation of the peptide bonds
30
How many steps are there for the translation of the mRNA molecule
Three step cycle that is repeated
31
What are the steps for translating mRNA
Starting point - An mRNA molecule and small subunit are holding on to each other. - A polypeptide chain is also holding on to the 3rd amino acid--> attached the the tRNA - Peptide chain has formed between amino acids 2 and 3 in the polypeptide chains Then... - An incoming (new) tRNA comes into the ribosomes A site (this is tRNA 4) - This tRNA carries the 4th amino acid. - The larger subunit on the ribosomes then moves (shifts slghtly) so that the 4th and 3rd amino acids are now in close proximity --> Forms a polypeptide bond between them. - The 3rd tRNA is then pushed away and moves onto the E site where it is ejected ( it is now devoid of the amino acid it was carrying ) This process then repeats with a new incoming tRNA
32
The polypeptide chain grows from which end
The 5* end to the 3* end on the mRNA | Goes from the N terminus to the C terminus on the polypeptide chain
33
What is the start site crucial for
Getting the correct reading frame If you don't start with the correct reading frame the whole sequence of your amino acid changes leads to protein garbage/mistranslated proteins
34
How do we set the correct reading frame
We have initiated tRNA In all organisms the codon that starts the protein off starts with AUG-->codes for methionine--> Only one codon codes for methionine This is the transcription start site
35
What is a charged tRNA
Any time a tRNA is attached to an amino acid we call it a charged tRNA
36
How does translation start
- The ribosome attaches onto the mRNA and looks for the AUG codon - Whatever reading frame is provided by the UAG is used - You now have the mRNA but it needs translating - You don't have the entire ribosome assembling at the very start. You have a small subunit attached with the initiator tRNA - The methionine is attached to the initiator tRNA
37
What is the initiator tRNA
It has initiation factors that are bound to it. These are proteins They are charged Charged methionine tRNA is attached to initiation factors (proteins) this together is call initiator tRNA It scans for fully formed mRNA
38
When is an mRNA fully formed
It has the RNA cap region and the polyA tail. | This is a fully formed stable mRNA molecule
39
What do the initiator tRNA and smaller subunit do
Goes along the cytoplasm and scans for the fully formed mRNA and when it comes across one it attached. Once its attached it starts scanning the genetic code that is present in the mRNA for the methionine codon which is within the mRNA. Once it finds the aug the inititator tRNA loses the initiation factors ( the proteins that were bound to it) and instead the larger subunit for the ribosomes comes and attaches to it. This fully formed ribosobes and now stable mRNA are now ready to start accepting the other tRNAs. Then the polypeptides start forming.
40
When do the ribosome stop making polypeptides
The whole thing stops when the entire ribosome complex comes into contact with the stop codon. We have three codons that code for the stop signal. Once the ribosome hits the stop codon, instead of incorporating an amino acid a water molecule is incorporated. When the water molecule is incorporated into the A site of the ribosome thats the signal for the mRNA to detach and the polpeptide to detach and the two ribosomal subunits to detach--> signifies the end of translation
41
What are the stop codons
UAA UAG UGA almost universal
42
Release factors
Proteins that come into play once the water molecule enters the A site and all of this detachment is occurring. This detachment is aided by other proteins that are called release factors.
43
How long is this formed polypeptide active within a cell
It depends on the type of protein e.g. if it is a structural protein that is part of the membranes in the cells/ hard tissue. The polypeptide survives for weeks/ months. other more metabolic proteins have polypeptides that are only active for seconds/ minutes /hours The stability of the protein within an organism depends on the function of the protein
44
How is the lifespan of a protein dictated / what is the lifespan of the protein dictated by
The rate of formation of the protein The rate of degradation of the protein The balance between protein formation and protein degradation dictates how much protein is available in a cell at any given point.
45
How does protein degradation occur
A dedicated machinery called Proteasome The proteasome is made of alot of proteases( proteins that are able to degrade other proteins)
46
What is the structure of a proteasome
Shaped like a barrel. The barrel is made up of all the proteases. At either end of these barrels you have cap proteins. These cap proteins form the structure but they also recognise which proteins is marked for degradation.
47
How do you mark proteins for degradation
There is a specific process for this. Within a cell. If a ubiquitin molecule is added on to a protein. This means the protein is now marked for protein degradation. The ubiquitin added to an amino acid is recognised by the cap proteins that are present on the proteasome.
48
What is the process of protein degradation
The cap proteins recognise the ubiquitin on proteins and the protein is then taken into the 'barrel' and then comes out broken down into different peptides or amino acids.
49
What is ubiquitin
A small organic molecule | Not a protein

MAT209 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions