Brainscape's Knowledge GenomeTM

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


See full index

BIOC192 2024 Melia > Lecture 16 - Genetic changes and protein function > Flashcards

Lecture 16 - Genetic changes and protein function Flashcards

1
Q

What carries out translation?

A

RIbosomes

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

Where does translation occur?

A

the cytoplasm

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

What is the purpose of translation?

A

Making a polypeptide chain using the message encoded by mRNA

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

What does mRNA do?

A

Tells amino acids the correct order to join together in

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

What are ribosomes?

A

complex structures made of protein and rRNA

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

How do ribosomes work?

A

They work like enzymes to catalyse protein synthesis (peptide bond reaction)

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

What are the four unique bases in DNA?

A

Adenine, Cytosine, Guanine, Thymine

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

What are the four unique bases in RNA?

A

Adenine, Cytosine, Guanine, Uracil

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

How is the four-base code of DNA translated to the 20 different amino acids?

A

The DNA/RNA is read in sets of three called codons

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

What is the codon system known as?

A

Since it is common across all life it is known as the universal genetic code

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

What reads the codons in mRNA?

A

tRNA

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

What is the complementary sequence to the mRNA codon called in tRNA?

A

anti-codon

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

What does cytosine pair with?

A

Guanine

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

What does adenine pair with?

A

Thymine (in DNA) or Uracil (in RNA)

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

What are the key features of tRNA?

A
  • Anticodon
  • Amino acid attached
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does tRNA create a peptide chain in the correct order?

A

Every codon/anti-codon sequence has a particular amino acid that it pairs with. The tRNA attaches to the amino acid and only the amino acid that matches that tRNA molecules anti-codon will be able to attach

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

What happens during translational initiation?

A

The ribosome, mRNA, and first tRNA come together to form the translational initiation complex. The first tRNA always codes for Methionine

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

What happens during translational elongation?

A

The ribosome moves along the mRNA, adding amino acids to the growing peptide chain

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

What happens during translational termination?

A

A stop codon indicates the peptide chain has all the necessary amino acids and causes the translational complex to break apart. The newly formed peptide chain releases

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

How many possible codons are there?

A

64

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How many amino acids are there?

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How many codons code for ‘stop’?

A

3

23
Q

Which amino acids have only one codon that codes for them?

A

Methionine, Tryptophan

24
Q

What does codon redundancy do?

A

As most amino acids have multiple codons that code for them, this allows for some flexibility in gene sequence without changing the protein

25
Q

What does genetic variation mean?

A

differences between the DNA sequences of members of the same species

26
Q

How much does the genome vary between humans?

A

0.1%

27
Q

What does genetic variation help with?

A
  • determine who is who
  • helps species survive
  • helps organisms adapt to their environment and any changes that occur
28
Q

What are different forms of a variant called?

A

alleles

29
Q

What are genetic variants classified by?

A
  • Number of DNA bases involved
  • Style of DNA sequence involved
  • Location of the change
30
Q

What is a SNP?

A

single nucleotide polymorphism, a single base change in the DNA sequence

31
Q

What is an INDEL?

A

insertion-deletion, the addition or removal of one or more bases

32
Q

Where do regulatory variants occur?

A

In transcription factor binding sites in the promoter

33
Q

Do genetic variants always have effects?

A

No depends on where it is in the genome and the type of variant

34
Q

Do variants in the regulatory region change expression of a gene?

A

Sometimes as they may change the amount of protein that is produced

35
Q

What type of variation may change the amino acid sequence?

A

Variants within the exon of a gene

36
Q

What do the majority of gene variants do?

A

Neutral - no effect

37
Q

What different things can SNPs that change a codon do?

A
  • Code for the same amino acid
  • Code for a different amino acid
  • Code for a stop, causing a truncated protein
38
Q

What may InDels that are not a multiple of 3 base pairs cause?

A

A frame shift, usually resulting in serious consequences for the protein

39
Q

What do the consequences of a missense genetic variant depend on?

A
  • Where in the protein the amino acid change occurs
  • how chemically similar/different the two amino acids are
  • Whether the amino acid breaks an essential structure
  • The original function of the protein
40
Q

Can every type of protein be affected by a genetic variant?

A

Yes

41
Q

When will a variant be lethal?

A

When a variant causes complete loss of function to a protein essential for life

42
Q

What contributes to the wide variety of differences between organisms?

A

The fact that every type of protein can have any type of genetic variant

43
Q

What is the gene name for the two alpha-haemoglobin chains?

A

HBA1

44
Q

How many coding variants are there for the HBA1 gene?

A

> 500

45
Q

What is the gene name for the two beta-haemoglobin chains?

A

HBB

46
Q

How many coding variants are there for the HBB gene?

A

> 1400

47
Q

What is a coding variant?

A

Any variant found in the exons of a gene

48
Q

What causes sickle cell anaemia?

A

Mutation in HBB E6V gene - 6th amino acid in beta-haemoglobin changed from glutamic acid to valine. Causing Hb protein to clog blood vessels

49
Q

What causes Methaemoglobinaemia?

A

Mutation in HBB H64Y - 64th amino acid in beta-haemoglobin changed from histidine to tyrosine. Fe3+ haem unable to bind oxygen

50
Q

What are the majority of recorded variants in Haemoglobin?

A

synonymous or benign missense changes

51
Q

What examples of pathogenic missense variants of haemoglobin?

A

Sickle cell anaemia, Methaemoglobinaemia

52
Q

What do consequences of missense genetic variants to an organism depend on?

A
  • How important the proteins job is
  • Whether another protein can compensate for the changed proteins function
  • The inheritance pattern of the protein
53
Q

How do tabby and solid cats vary?

A
  • ASIP in cats creates tabby stripes
  • Due to genetic variant : 2-bp deletion in exon 2 of ASIP (c.123delCA), known as the “non-agouti allele” solid cats have a non functioning ASIP
  • Causes a frameshift which disrupts the proteins function

BIOC192 2024 Melia (36 decks)

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