Clonal Selection/Antibody Structure

Question 1

what is the Clonal Selection Theory in reference to?

Answer 1

immune specificity and memory

Question 2

in the Clonal Selection Theory, what does recognition of an antigen signal a cell to do?

Answer 2

undergo proliferation

Question 3

what do proliferating lymphocytes differentiate into?

Answer 3

effector cells and memory cells

Question 4

clonal selection holds true for _________________

Answer 4

both B and T cells

Question 5

what secretes antibodies (Ab)?

Answer 5

effector B cells (plasma cells)

Question 6

what are immunoglobulins?

Answer 6

antibodies because they are globular, not fibrous

Question 7

an antibody molecule monomer consists of ___________________

Answer 7

two heavy (H) chains and two light (L) chains

Question 8

what bond links an H chain to an L chain?

Answer 8

disulfide (S-S) bonds

Question 9

what produces the “hinge region” in an antibody molecule monomer?

Answer 9

the disulfide bond between the heavy (H) chains

Question 10

what does cleaving the antibody molecule at the hinge regions result in?

Answer 10

Fab (two identical) and Fc (one) fragments

Question 11

what makes up the Fab fragment?

Answer 11

one complete light chain and part of one heavy chain

Question 12

how many binding sites for antigens are on one fab fragment?

Answer 12

one

Question 13

what does bivalency refer to?

Answer 13

two Fab fragments per antibody molecule, so two identical binding sites for an antigen on each monomer

Question 14

what region (Fc or Fab) determines the specific effector function(s) the immune system will take on an antigen-antibody complex?

Answer 14

Fc region

Question 15

what is a region of about 100 amino acids tightly folded in an immunoglobulin chain?

Answer 15

a domain

Question 16

the light chain has ____ domains and the heavy chain has ____ domains

Answer 16

two
four, sometimes five

Question 17

what are the domains called at the N-terminus in both the heavy and light chains?

Answer 17

variable regions
VH and VL

Question 18

what are the domains away from the N-terminus called?

Answer 18

constant regions

Question 19

what are the parts of antibodies that actually make contact with the antigen?

Answer 19

complementarity-determining region (CDR)

Question 20

what does idiotype refer to?

Answer 20

the unique antigen specificities of an antibody

Question 21

how many classes/isotypes of immunoglobulins are there in mammals?

Answer 21

five

Question 22

what is IgM found in the serum as?

Answer 22

a pentamer

Question 23

what holds the pentamer together?

Answer 23

J chain polypeptide (joining chain)

Question 24

what classes can form polymeric immunoglobulins?

Answer 24

IgM and IgA

Question 25

what is IgA found in the serum as?

Answer 25

monomers and dimers

Question 26

what is the IgA in mucosal secretions called?

Answer 26

secretory IgA

Question 27

what are the two types of light chains?

Answer 27

kappa and lambda

Question 28

each IgA dimer includes one _________________ and one additional polypeptide called ___________________

Answer 28

J chain polypeptide secretory component (SC)

Question 29

what is multiple myeloma?

Answer 29

cancer of a plasma cell

Question 30

is myeloma protein a normal anitbody?

Answer 30

yes, just produced in very large amounts

Question 31

what are the two types of domains that make up an immunoglobulin molecule?

Answer 31

variable regions (for heavy and light chains) constant regions (for heavy and light chains)

Question 32

each binding site has ___ complementarity-determining region(s): ___ variable heavy CDR(s) and ___ variable light CDR(s)

Answer 32

six three three

Question 33

what is the difference between idiotype and isotype?

Answer 33

idiotype: antigenic specificities of an antibody isotype: class of immunoglobulin molecule