ILA 1 - IMMS

Question 1

Transcription (what is it, location, stages)

Answer 1

production of mRNA, Nucleus of cell

initiation, elongation, termination

Question 2

Process of transcription

Answer 2

RNA polymerase binds to the promoter region, elongation occurs as the RNA polymerase moves in a 5-3 direction attaching nucleoside triphosphates . RNA polymerase reaches the terminator enzyme detach and the DNA rewinds

Question 3

Topoisomerase

Answer 3

Unwinds the DNA section

Question 4

Topoisomerase

Answer 4

Unwinds the DNA section

Question 5

TATA box

Answer 5

30 bases long which is a binding sight for transcription factors

Question 6

TATA box

Answer 6

30 bases long which is a binding sight for transcription factors

Question 7

Transcription factors

Answer 7

class of protein that bind to promoter on DNA to activate transcription –> control gene expression

Question 8

Splicing

Answer 8

introns removed from the mRNA

Question 9

Translation (what is it, location)

Answer 9

producing polypeptides from mRNA, occurs in the cytoplasm of a ribosome.

Question 10

Start codon

Answer 10

AUG –> methionine

Question 11

tRNA

Answer 11

tRNA molecules bind to a specific amino acid. And the other end have a specific anti-codon

Question 12

Stages of translation

Answer 12

large ribosome sub unit binds the start codon to the P site, ribosome moves along towards 3’ end. Peptide bond formed between AA in P and A site (peptidyl transferase). Continues till it has reached a stop codon

Question 13

Single nucleotide polymorphism (SNP)

Answer 13

Variation at a single nucleotide position in a DNA sequence (occurs on 1 in 300 bases). Often does not cause any issues

Question 14

Mis-sense variation

Answer 14

One base to another base

Question 15

Non-sense variation

Answer 15

changes the base to make a stop codon

Question 16

Sickle cell mutation

Answer 16

Single nucleotide substitution A –> T (glutamic acid to valine) GAG –> GTG

Question 17

consequences of nucleotide alteration

Answer 17

different complimentary base pairing, different anti-codon, different AA, different polypeptide chain, different primary structure, different protein shape, different function

Question 18

Conformation change in sickle cell (protein level)

Answer 18

glutamic acid –> valine.
abnormal beta globin = HbS. The amino acid is less polar = favours hydrophobic reactions causing S sub units to stick together to form long rigid molecules. Sickle cell from the internal binding to cytoskeleton

Question 19

conformation change of haemoglobin consequences

Answer 19

haemoglobin becomes less soluble under decreasing oxygen concentrations = polymerises into crystals. Loses elasticity so cannot fit through capillaries = endothelial damage and inflammatory response = pain and can cause ischaemia

Question 20

How is sickle cell inherited?

Answer 20

autosomal recessive genetic condition

Question 21

Treatment of sickle cell

Answer 21

Can be treated with feotal Hb which increases the concentration of NO = increases transcription of gamma haemoglobin (not beta) so no deformity