Immunoglobulins 2

Question 1

True of false.

IgG has 2 identical binding sites?

Answer 1

True

Question 2

How many classes of immunoglobulins?

Answer 2

5

Question 3

What is the anagram for the classes of immunoglobulins?

Answer 3

GAMED

Question 4

Immunoglobulins can also be classified a different way, how?

Answer 4

Classed by their light chain, 2 types kappa and lambada

Question 5

What’s the fab region?

Answer 5

Antigen binding

Question 6

What’s the Fc region?

Answer 6

Effector function

Question 7

Description of lgG?

Answer 7

Most abundant in serum

4 lgG subclasses

Question 8

Function of LgG?

Answer 8

Binding the antigen
Neutralising bacterial toxins
Inactivating viruses

Question 9

What’s a complement system?

Answer 9

A collection of serum glycoproteins 15-20 proteins that initiate a cascade that perforate cell membranes

Question 10

Complement roles

Answer 10

Opsonisation
Activation/re activation of cells
Regulation of antibody responses

Question 11

3 pathways of complement activation

Answer 11

Classic
Lectin
Alternative

Question 12

Describe the classic pathway (4 steps)

Answer 12

1- C1 binds to the fc region of IgG
2-C1 activated to an active protease when cross linked to 2 complexes
3-C9 forming a pore through membrane
4-cascade also attracts phagocytotic cells

Question 13

2 receptors on membrane surface

Answer 13

Fc receptors

Complement receptors

Question 14

Antibody dependant cell mediated cytotoxicity(ADCC)

Answer 14

1. Antibody bound to virus infected cell
2. links to Fc receptor of natural killer cell
3. Antibody acts as sirens alerting NK cells which recognise and secrete cytokines to attach and kill the infected cell

Question 15

Human Fc receptors for IgG differs in:

Answer 15

Function
Affinity for the Fc fragment of antibody
Cellular distribution

Question 16

Important roles of IgG?

Answer 16

Cross the placenta (transcytosis)

Provides strong immunity

Question 17

Immunoglobulin A description

Answer 17

10% in serum

Exists as a monomer

Question 18

IgA function

Answer 18

Protect internal surfaces of body against microorganisms

Question 19

J chain?

Answer 19

Helps to bind dimer (lgA)

Question 20

Immunoglobulin B description

Answer 20

Monomer form
Heavy chains
Usually on B cells
Secreted in blood (primary immune response)
Protection against infections

Question 21

Immunoglobulin D

Answer 21

4 basic polypeptide chains
Hinge region more extended
Found on surface of b lymphocytes

Question 22

Immunoglobulin E

Answer 22

4 polypeptide structure
Very low serum conc.
high affinity for mast cells
Mediate the hypersensitivity reactions responsible for symptoms of hayfever and shit

Question 23

4 step process of IgE?

Answer 23

1- IgE bonds to allergen

2. receptor on mast cell bonds to IgE complex and triggers mast cell to secrete amines (degranulation)
3. histamine secreted
4. esinophils attracted (due to factors secreted by mast cells)