L53 part 2

Question 1

Surface IgM acts as what?

Answer 1

The B cell antigen receptor

Question 2

B cells secrete their antibody when?

Answer 2

Only when they bind the antigen and have expanded into the effector cells

Question 3

What are the products of B cells?

Answer 3

Antibodies

Question 4

Antibodies consist of what types of chains?

Answer 4

2 identical heavy chains and 2 identical light chains

Question 5

The chain itself can contain how many regions?

Answer 5

2

Question 6

What are the 2 different regions in a chain?

Answer 6

The variable and the constant region

Question 7

what is the variable region called and how many forms are there?

Answer 7

Fab and a variety of forms

Question 8

What is the constant region called and how many forms are there?

Answer 8

Called the Fc region and there are 5 forms

Question 9

Which region binds the antigen?

Answer 9

The variable region, Fab

Question 10

What is antibody affinity?

Answer 10

the measure of the strength of the bond between an antibodies binding site and an antigen

Question 11

What are the possible antibody isotypes produced by a single B cell?

Answer 11

G, D, E, A and M

Question 12

What are the 5 classes of antibodies determined by?

Answer 12

The Fc region

Question 13

Where is IgM found and where is it secreted to?

Answer 13

Found on the membrane of naive B cells, secreted into plasma as a pentamer

Question 14

Where is IgG found

Answer 14

High concs in plasma and tissue fluids

Question 15

Where is IgA found?

Answer 15

High concs in mucosal secretions, often a dimer

Question 16

Where is IgE found?

Answer 16

Low levels in plasma, tissue fluids, bound to mast cells

Question 17

Antibody IgA binding to an antigen on a pathogen results in what in terms of the Fab region?

Answer 17

Prevention of pathogen binding at mucosal surfaces

Question 18

Anitbody IgG and IgM binding to an antigen on a pathogen results in what in terms of the Fab region?

Answer 18

Neutralisation of toxin

Question 19

Anitbody IgM binding an antigen on a pathogen results in what in terms of the Fc region?

Answer 19

Triggering the classical pathway of the complement cascade

Question 20

Antibody IgG binding an antigen on a pathogen results in what in terms of the Fc region?

Answer 20

Opsonisation, Triggering the classical pathway of the complement cascade, Transplacental immunity

Question 21

What is Opsonisation?

Answer 21

The Fc region binds directly to the Fc receptors FcR on phagocytes

Question 22

Antibody IgE binding an antigen on a pathogen results in what in terms of the Fc region?

Answer 22

Triggers degranulation of mast cells, eosinophils

Question 23

What happens during opsonisation, so when the Fc region binds directly with FcReceptors

Answer 23

Induces the release of cytotoxic products from macrophages and NK cells

Question 24

When does isotype switching occur?

Answer 24

Only after B cells have been stimulated by antigens to make IgM

Question 25

what happens in term of dna recombination for isotype switching?

Answer 25

Irreversible DNA recombination

Question 26

What determines isotype production?

Answer 26

External signals from T cells and the pathogen

Question 27

is there an increase or decrease in affinity after the newly produce isotype?

Answer 27

Increase

Question 28

What are the 2 types of specific immunitiy?

Answer 28

Passive and active

Question 29

What is passive immunity and when is it commonly used?

Answer 29

Transfer of serum, mostly IgG, from a specifically immunised individual. So its a rapid response and short lived. Used for tetanus, hepatitis A

Question 30

what is active immunity

Answer 30

When an individual is exposed to a foreign antigen, slow response