Red Cell Membrane

Question 1

Which antigens does the red cell membrane lack?

Answer 1

HLA antigens - human leukocyte antigens which are found on many cells in the body, transplantation antigens.

Question 2

What is the red cell bilayer made up of?

Answer 2

50% protein
20% phospholipids
20% cholesterol
10% carbohydrate

Question 3

What are the two types of carbohydrate on the red cell membrane?

Answer 3

Integral (penetrating the lipid bilayer) or peripheral

Question 4

What are the 6 proteins which have a structural role in the red cell membrane?

Answer 4

3 (band) , p 4.1, 4.3 (band), actin, ankyrin, spectrin.

Question 5

What are the 4 principle transmembrane glycoproteins?

Answer 5

Glycoprotein A and C, Rh associated glycoprotein (RhAG) and band 3

Question 6

What is the role of alpha and beta spectrin in the red cell membrane?

Answer 6

In the cytoplasm of the cell, these are major structural components.

Question 7

What is hereditary spherocytosis?

Answer 7

Gene defect in protein which interacts between the skeleton membrane and the lipid bilayer.
Mutation in the genes producing spectrin and ankyrin.

Question 8

What are the 5 glycoproteins components of the red cell membrane with transport functions?

Answer 8

• Glut-1 (glucose and ascorbic acid- VitC)
• Band 3 - anion exporter = exchanging bicarbonate ion and chloride.
• Rh D protein- ammonia and CO2 transport.
• Kidd (blood group) - red cell, renal and urea transport.
• Aquaporin - H2O, CO2, O2

Question 9

What are the 3 main enzymes associated with the red cell membrane?

Answer 9

Na/K/ATPase
Carbonic anhydrase
Alkaline phosphatase
Lactate dehydrogenase.

Question 10

What is the name of the adhesive protein which is a part of the band 3/Rh complex which interacts with macrophages?

Answer 10

CD47

Question 11

What does the Duffy (blood group) recept?

Answer 11

It is an antigen receptor for chemokines (DARC)

Question 12

Which glycoproteins are involved in the membrane of the internal cytoskeleton?

Answer 12

A, B, C and D

Question 13

What is the role of CD 59?

Answer 13

This is a membrane inhibitor - regulatory protein

- reactive lysis

Question 14

What is paroxysmal nocturnal haemoglobinuria PNH?

Answer 14

This is a deficiency of CD59 due to a mutation and is exposed to a haemolytic condition resulting in severe hemolysis .

Question 15

What is the role of CD 55?

Answer 15

This is a decay accelerating factor - a complement regulatory protein.
Neutralises complement proteins, with PNH - lacks this protein.