Antibodies--Diebel

Question 1

Which Ig is found in its secreted, pentameric form?

Answer 1

IgM

Question 2

Which Ig is found in its secreted, dimer form?

Answer 2

IgA

Question 3

What is the J-chain?

Answer 3

protein segment that holds IgM and IgA in their respective multimeric forms

Question 4

What are the two subtypes of light chains?

Answer 4

lambda and kappa

Question 5

T/F one antibody can have both a lambda and a kappa light chain

Answer 5

F

one antibody has either identical lambdas or identical kappas

Question 6

Valence of IgG

Answer 6

2

Question 7

Valence of IgA

Answer 7

4

Question 8

Valence of IgM

Answer 8

5 (tricky, should theoretically be 10)

Question 9

Which IgG binds complement best?

Answer 9

IgG3

Question 10

Best Ig for fixing complement

Answer 10

IgM

Question 11

Best Ig for toxin neutralization

Answer 11

IgG (also IgA)

Question 12

Best Ig for mast cell/basophil degranulation

Answer 12

IgE

Question 13

Best Ig for combined toxin neutralization and antiviral activity

Answer 13

IgA

Question 14

This Ig is present to fight of parasitic infections

Answer 14

IgE

Question 15

VDJ segments are found in what part of antibody?

Answer 15

heavy segment

Question 16

VJ segments are found in what part of antibody?

Answer 16

light segment (either lambda or kappa)

Question 17

What is the function of RAG recombinases?

Answer 17

recognize random signals and cut and paste new base pairs in

Question 18

What is the function of exonucleases in antibody recombination?

Answer 18

cut off some base pairs before ends of transcript are joined

Question 19

What is the function of terminal deoxynucleotidyltransferase?

Answer 19

add random base pairs

Question 20

What is the function of activation-induced cytodine deaminase?

Answer 20

converts random cytosines to uracils: guanine mismatch

Question 21

What is an isotype for antibodies?

Answer 21

different classes (ie IgG vs IgM)

Question 22

What is an allotype for antibodies?

Answer 22

allelic variation–one from mom and one from dad

Question 23

What is an idiotype for antibodies?

Answer 23

different specificities, ie one for a certain toxin

Question 24

C1q binds what area of antibodies?

Answer 24

two adjacent Fc regions

Question 25

Why is IgM better at activating complement than IgG?

Answer 25

IgM is found in its pentameric form, therefore 2 adjacent Fc regions are always next to one another. 2 adjacent Fc regions activate C1q, the first molecule in the complement cascade

Question 26

This very special CD is located on B-cells and helps them talk to CD4+ T-cells

Answer 26

CD40 (it binds CD40L, CD40 ligand on the CD4+ T-cell)