Chapter 17 Part 2

Question 1

What are the three effector functions of the antibody molecules?

Answer 1

• bind to and neutralize a bacterial toxin
• opsonization: coat the pathogen to promote phagocytosis
• activate complement

Question 2

What is the structure of antibody?

Answer 2

Both contain one constant and one variable region
- 2 heavy chains (inner and long) (3/4 domains)
- 2 light chains (outer and short) (one domain)
- bonded by disulphide bonds
- Fab fragment (heavy inner, light outer)
- Fc fragment (heavy chain and bonded to cell like root)

Question 3

another name for antibody

Answer 3

immunoglobins

Question 4

What is a polyclonal response

Answer 4

when antigen have multiple different epitopes each B cells must make different antibodies for ONE antigen

Question 5

another name for the hypervariable region on antibody

Answer 5

complementary determining regions (5-10 amnio acids)

Question 6

where are the 6 hypervariable chains on an antibody

Answer 6

on the Fac fragment

Question 7

What are the 3 steps in antigen recognition diversity?

Answer 7

1) somatic recombination
2) junctional diversity
3) combinational diversity

Question 8

Explain Somatic Recombination

Answer 8

The heavy chain is chosen first
- different V, D & J segments are joined to create a variable region
Light chain is chosen after
- different V and J segments are joined together

Question 9

Explain junctional diversity

Answer 9

new nucleotides are added into the V and J segments of the light chain and D and J on the heavy chain

Question 10

Explain combinational diversity

Answer 10

different light chains are combined with already generated heavy chains

Question 11

What are the five classes of antibodies?

Answer 11

• IgM
• IgG
• IgE
• IgA
• IgD

Question 12

Where and when does the switching into a different class of antibody taking place?

Answer 12

germinal centre of lymph nodes after B cell activation

Question 13

Which receptor (immnoglobin/antibody) is released first?

Answer 13

IgM

Question 14

what differentiates the class of antibodies?

Answer 14

their light chains

Question 15

how does a helper T cell help activate a B cell to secrete an antibody?

Answer 15

it sends the B cells to the germinal center of the lymph node to be class/isotype switched

Question 16

why is the IgM the first antibody to be secreted?

Answer 16

it is the default antibody, it doesn’t get changed unless it is sent to the germinal center by the Helper T cell

Question 17

What is somatic hypermutation?

Answer 17

B cells are sent to the germinal centre where they change the antibodies of B cells so they generate an antibody with higher affinity of the antigen

Question 18

What does affinity maturation mean?

Answer 18

what it is called after the B cell has undergone somatic hypermutation and now are selected to under class/isotype switching helped by the helper T cells

Question 19

What is a clonal selection hypothesis?

Answer 19

after activation the B cell will multiply itself

Question 20

Where does T cell maturation take place?

Answer 20

thymus but they originate in the bone marrow

Question 21

what does MHC restriction mean?

Answer 21

when T cells recognize self antigens (they get eliminated in thymus)

Question 22

how do t cells get activated?

Answer 22

by dendritic cells

Question 23

What is herd immunity?

Answer 23

when majority of a population is immune to a virus so they chance of someone susceptible to the virus catching it is low

Question 24

what is a plasma cell

Answer 24

short lived B cells that produce large amount of antibodies

Question 25

what is a memory cell

Answer 25

activated B cells that remain in the lymphoid tissue in case the antigen reappears in the body

Question 26

where the 2 stages of the adaptive immune response?

Answer 26

1) Humoral- antibody secretion
2) Cell Mediated - killing infected cells