Hemoglobin structure, Hb switching, detection of abnormal Hb

Question 1

Structure of Hemoglobin and HbA?

Answer 1

metalloprotein w. quaternary structure w. 4 protein subunits. Each subunit made
up of protein + non protein heme group (Fe2+ is site of oxygen binding,
coordinates w. four nitrogens in centre of heterocyclic ring) can also bind histodine
residues
Iron containing metalloprotien, transports oxygen in rbc from lungs to tissue
Tetrameric protein: consists of 2 alpha chains + 2 beta chains; 98% of
haemoglobin A

Question 2

HbA2?

Answer 2

HbA2 is another type: w. 2 alpha chains + 2 delta chains

Question 3

What chromosomes are for beta globin and alpha globin genes?

Answer 3

chromosome 11 for beta and chromosome 16 for alpha

Question 4

Hb switching?

Answer 4

Foetal haemoglobin’s affinity for oxygen is higher that adult’s because foetus must
extract oxygen from maternal blood across the placenta.
When foetal haemoglobin switched off after birth, normal children begin to
produce HbA. Sufferers’ from sickle cell disease produce defective haemoglobin

Question 5

Detecting abnromal Hb?

Answer 5

Electrophoresis on agar substance. Diff hemoglobin diff charges therefore move at diff speeds in gel

Question 6

Unstable hemoglobinopathy?

Answer 6

single amino acid exchange can lead to disintegration of Hb molecule.

Question 7

Can determine deficency such as

Answer 7

Thalassemia