Haemoglobin and thalassaemia

Question 1

Structure of RBC

Answer 1

Contain haemoglobin (approx 640 million molecules in each cell)

No nucleus or mitochondria

3.5-5 x10^12/L

Question 2

Normal composition of haemoglobin in the body (MW, conc, produced/destroyed, Fe)

Answer 2

In adults = 120-165g/L

90 mg/kg produced and destroyed every day

each gram contains 3.4mg Fe

64-64.5kDa

Question 3

Where is haemoglobin synthesised

Answer 3

Haem = mitochondria

Globin = ribosomes

Question 4

When does haemoglobin synthesis occur

Answer 4

During the development of RBC, beginning in pro-erythroblast:

65% = erythroblast stage

35% = reticulocyte stage

Question 5

Draw the synthesis of haemoglobin

Answer 5

Question 6

What are the proteins that haemoglobin can be contained in

Answer 6

Myoglobin

Cytochromes

Peroxidases

Catalases

Tryptophan

Question 7

Describe the structure of haem

Answer 7

protoporphyrin ring and a central iron atom (ferroprotoporphyrin)

can reversibly combine with oxygen

Question 8

Where is haem is synthesised

Answer 8

Mainly in the mitochondria with the aid of the enzyme ALAS

Question 9

Which structure is the same in all types of Hb (haem or globin)

Answer 9

Haem

Question 10

Describe the 2 globin clusters

Answer 10

Contain the 8 globin chains

α cluster = on the short arm of chrom16 (α, ζ globin chains)

β cluster = on the short arm of chrom11 (β, γ, δ, ε globin chains)