21 15-16

Question 1

Structure of an antibody monomer?

Answer 1

Four looping polypeptide chains linked together by disulfide bonds.

Heavy and light chains, Y shaped structure.

Antigen binding site is at the top of Y, stem region determines mechanism of action.

Question 2

Five classes of antibodies/imunoglobulins?

Answer 2

Ig -MADGE

Question 3

IgM

Answer 3

First Ig class released by plasma cells during infection.

Big gun, 10 binding sites (pentameter).

Potent agglutinator.

Question 4

IgA

Answer 4

Found in body secretions - tears, sweat, etc.

Help prevent attachment of pathogens to epithelial (incl. mucous membranes and epidermis) surfaces.

Question 5

IgD

Answer 5

Receptor of B cell

Question 6

IgG

Answer 6

75-85% of all circulating antibodies - kingpin.

Protects against pathogens in blood and lymph.

Is transferred from mother to child via placenta.

Universal

Question 7

IgE

Answer 7

Mediates inflammatory and allergic reactions.

Stem end binds to mast cells and basophils and when an antigen binds histamine is released.

Question 8

Function of antibodies?

Answer 8

After antigen binds to antibody…. PLAN

P - precipitation, pulls soluable antigen out of solution and make it a bigger target.

L - Lysis, complement/poke a hole in a cell

A - agglutination, antibodies cross-link antigens on cells causing clumping

N - - neutralization, antibodies block specific sites on viruses or bacterial exotoxins causing the to lose their toxic effects.

PAN enhance phagocytosis,
L enhances phagocytosis, inflammation and leads to lysis.

Question 9

Clinical uses of monoclonal antibodies

Answer 9

Monoclonal antibodies, produced by descendents of a single cell, are pure antibody preparations specific for a single antigenic determinant.

Used to diagnose: pregnancy, STDs, cancer, hep, rabies.

Used to treat: leukemias, lymphomas, cancers that can be accessed by injected antibodies.

Question 10

P

Answer 10

P - precipitation, pulls soluable antigen out of solution and make it a bigger target.

Question 11

L

Answer 11

L - Lysis, complement/poke a hole in a cell

Question 12

N

Answer 12

N - - neutralization, antibodies block specific sites on viruses or bacterial exotoxins causing the to lose their toxic effects.

Question 13

A

Answer 13

A - agglutination, antibodies cross-link antigens on cells causing clumping