MOLECULAR BIOLOGY OF THE GENE Flashcards Preview

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Flashcards in MOLECULAR BIOLOGY OF THE GENE Deck (25)
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1
Q

how many codons are there?

A

64

2
Q

how many amino acids are there?

A

20

3
Q

which base is degenerate?

A

3rd

4
Q

what is the start codon?

A

AUG codes for methionine (Met)

1st AA in a polypeptide

5
Q

what is the one gene -one protein hypothesis?

A

o

6
Q

what is alternative splicing?

A

exons can be joined together in a

variety of ways

7
Q

what can errors in gene expression cause?

A

many uncommon disorders
can also influence the predisposition of many common diseases such as breast cancer, lung cancer, prostate cancer and blood cancer

8
Q

how do transcription errors lead to disease?

A

Over-expression of the TF MYC is found in numerous cancers

If one copy of the gene encoding the TF is mutated this can also lead to disease

9
Q

what is haploinsufficiency?

A

where one copy of the gene is not enough e.g. p53 gene

10
Q

what is dominant mutation?

A

where a change in the gene sequence generates change in the protein that exerts dominance over the wild-type e.g. TFCP2L3 gene and genetic deafness

11
Q

how do mRNA processing errors occur?

A

involves errors in alternative splicing

12
Q

how does cystic fibrosis occur?

A

Mutations found in the exon 7 of SMN1 gene.

As a result, the exon 7 is skipped and the protein produced is non-functional

13
Q

what are mRNA translation errors?

A

Mutations that affect translational efficiency

14
Q

give examples of mutations in key translation proteins that lead to diseases

A

Translation initiation factors, e.g. eIF2 gene - a neurodegenerative disease called VWM
Release factors, e.g. eRF3 gene – gastric cancer
Mutations affecting the tRNA transfer proteins or the ribosome itself

15
Q

what is Gel Electrophoresis of DNAs/RNAs?

A

g

16
Q

how does gel electrophoresis work?

A

DNA is negatively charged (-):
Anode (-)
Cathode (+)
So will move from the anode to the cathode

17
Q

what is produced from gel electrophoresis?

A

A gel image loaded with DNAs

18
Q

what is western blot?

A

w

19
Q

what is western blot used for?

A

to detect proteins

20
Q

what are the steps involved in western blotting?

A
Sample preparation
Gel Electrophoresis
Blotting (or transfer)
Blocking
Antibody Probing
Detection
21
Q

how can we detect gene expression?

A

Polymerase Chain Reaction (PCR)

22
Q

what is PCR?

A

p

23
Q

what does PCR allow?

A

Enables the amplification of a specific region of DNA from just a single molecule of starting material

24
Q

what does gene expression profiling allow?

A

Detects how many copies of a gene (genes) you have

Idea of the regulation of gene expression at a given time

25
Q

what is PCR used for?

A

Diagnostics
Gene cloning
Legal disputes