02 Molecular Biology and its relevance to Medicine

Question 1

Symptoms of sickle cell disease

Answer 1

• Low number of RBC
• Repeated infections
• Periodic pain
• Jaundice

Question 2

Describe the structure of haemoglobin

Answer 2

Tetramer with α2β2 structure

Question 3

Name of alpha protein subunit and which genes is it coded by?

Answer 3

HBA2 (alpha protein subunit)

HBA1 and HBA2 genes

Question 4

Name of the beta protein subunit and which gene is it coded by?

Answer 4

HBB1 (beta protein subunit)

HBB gene

Question 5

Which state is the deoxy form of haemoglobin?

Answer 5

T-state (tense state)

Question 6

Which state is the oxy form of haemoglobin?

Answer 6

R-state (relaxed state)

Question 7

Which state is the oxy form of haemoglobin?

Answer 7

R-state (relaxed state)

Question 8

Why do the shape of blood cells from sickle cell disease patients appear like a sickle?

Answer 8

Abnormal interactions between beta chains cause haemoglobin form fibers -> lead to distortion of cell shape

Question 9

What is the advantage of being heterozygous in sickle cell anaemia?

Answer 9

10 fold reduced risk of severe malaria

Question 10

Cause of alpha thalassaemia

Answer 10

Reduced alpha-globin

Question 11

Cause of beta thalassaemia

Answer 11

Reduced beta-globin

Question 12

Symptoms of cystic fibrosis

Answer 12

Salty skin, poor growth, thick sticky mucus, chest infections