Molecular Biology

Question 1

Does insulin require PTMs

Answer 1

No

Question 2

A person’s genotype can be determined by

Answer 2

PCR-RFLP, fluorescence based methods, sequencing methods

Question 3

What system is insulin best produced in

Answer 3

Bacteria

Question 4

Does EPO require PTMs

Answer 4

Yes, glycosylation

Question 5

What system is EPO best produced in

Answer 5

Eukaryotic system (mammalian) : Chinese hamster ovary cells

Question 6

Does antithrombin require PTMs

Answer 6

Yes (carboxylation)

Question 7

What system is antithrombin best produced in and why

Answer 7

Transgenic animal (goats, pharming). Carboxylation is tricky so won’t occur in a cell culture

Question 8

What is the central dogma of molecular biology

Answer 8

DNA -> mRNA -> protein

Question 9

What is the basic structure of all genes

Answer 9

Promoter region and transcribed region

Question 10

What is a gene

Answer 10

Region of DNA which makes one mRNA molecule

Question 11

What is different about prokaryotic genes

Answer 11

No introns, prokaryotes don’t have the ability to splice. No nucleus, transcribe and translate DNA simultaneously

Question 12

What is added to mRNA to prevent degradation in eukaryotic cells

Answer 12

5’G cap and 3’ poly-A tail

Question 13

What is present in the promoter region of a gene

Answer 13

Transcription factor binding sites and RNA polymerase binding site

Question 14

What are transcription factors

Answer 14

Proteins that bind DNA and control promoter binding of RNA polymerase (can have more than one simultaneously)

Question 15

What are the two types of transcription factors

Answer 15

Activators (turn on), repressors (turn off) by blocking RNA polymerase from binding

Question 16

How do transcription factors work

Answer 16

Use physical connections to turn genes on/off

Question 17

Why is transcriptional control important

Answer 17

So that cells can have different genes turned on for their different functions

Question 18

Which transcription factors are present differs:

Answer 18

Between cells and over time

Question 19

What are ribosomes made of

Answer 19

rRNA and protein: work like enzymes to catalyse protein synthesis (but aren’t actually enzymes)

Question 20

What is meant by the universal genetic code

Answer 20

Codons code for the same amino acids in all organisms

Question 21

What are the three stages of translation

Answer 21

Initiation, elongation, termination

Question 22

What happens in initiation of translation

Answer 22

Ribosome, mRNA and first tRNA come together to form translation initiation complex

Question 23

What happens in elongation of translation

Answer 23

Ribosome moves along mRNA adding amino acids to chain

Question 24

What happens in termination of translation

Answer 24

Stop codon is reached, translation complex breaks apart

Question 25

What are the only non-redundant amino acids

Answer 25

Met and Trp

Question 26

What is genetic variation

Answer 26

Differences at the same locus between DNA sequences of members of the same species

Question 27

Why is genetic variation important

Answer 27

Helps us determine who is who, helps a species survive, helps organisms adapt to their environment

Question 28

What is a genetic variant

Answer 28

A specific difference between individuals

Question 29

What are the two types of genetic variants we need to know

Answer 29

SNP and InDel

Question 30

What might a variant in an intron result in

Answer 30

Different expression of the gene (different amount produced)
(Stop codon can’t be coded for in an intron)

Question 31

What is a missense mutation

Answer 31

One different amino acid coded for

Question 32

What is a nonsense mutation

Answer 32

Early stop codon coded for

Question 33

What do the consequences of a missense mutation depend on

Answer 33

Where in the protein it occurs (e.g active site), how chemically different amino acids are (e.g polar charged, non polar), whether amino acid breaks essential structure (e.g glycine helix breaker, cysteine disulfide bond)

Question 34

What does the HBB E6V variant result in

Answer 34

Glutamic acid to valine, causes aggregation of haemoglobin due to hydrophobic interactions, sickle cell anaemia

Question 35

What is HBB

Answer 35

Haemoglobin B subunit gene

Question 36

What does the HBB H64Y variant result in

Answer 36

Histidine to tyrosine, Fe2+ of haem able to be oxidised to Fe3+, can’t bind oxygen

Question 37

The consequences of a missense mutation to the organism depend on

Answer 37

How important the protein’s job is, whether another protein can compensate for the lost function, whether the protein lost or gained a function, the inheritance pattern of the protein

Question 38

What mode of inheritance do gain of function alleles have

Answer 38

Dominant

Question 39

What mode of inheritance do loss of function alleles have

Answer 39

Recessive

Question 40

What is retinitis pigmentosa

Answer 40

Retinal degenerative disease caused by variants in rhodopsin receptor protein. Dominant inheritance pattern, one variant allele, gain of function

Question 41

What is phenylketonuria

Answer 41

Monogenic disease resulting in disruption of pathway from phenylalanine to tyrosine, resulting in a build up of phenylalanine causing brain damage

Question 42

What processes enable genotyping

Answer 42

PCR-RFLP, fluorescence based methods, genome sequencing

Question 43

What components are needed in PCR

Answer 43

DNA sample, primers, DNA polymerase (heat tolerant), DNA nucleotides