Antibody and antigen

Question 1

What is a B-cell receptor

Answer 1

Membrane bound Ig on the B-cell surface

Question 2

What is an antibody

Answer 2

Secreted Ig of the same antigen specificity as the BCR

Question 3

What are antigens

Answer 3

foreign and endogenous substances recognized by the immune system

Question 4

what is an immunogen

Answer 4

antigen that induces an immune response

Question 5

What is immunoglobulin that is membrane bound

Answer 5

B-cell receptor

Question 6

What is the function of immunoglobulin

Answer 6

Both BCR and secreted Ab bind Ag, Ag binding to the BCR signals B cell to: divide, differentiate, secrete Ab

Question 7

What is the basic structure of antibody

Answer 7

Two identical heavy chains and two identical light chains

Question 8

What are the divisions of Light chains of antibodies

Answer 8

Variable region (both on light and heavy), and constant region

Question 9

What is a characteristic of variable region

Answer 9

varies between different B-cells (daughter B cells are identical)

Question 10

What is a characteristic of a Constant region

Answer 10

Ab from same animal have similar constant region

Question 11

What is a paratope

Answer 11

combined portion of light and heavy variable regions of antibody, 2 identical Ag binding sites per core Ab structure

Question 12

What does the flexible portion on constant region of heavy chain do

Answer 12

allows better binding of antibody in diverse situations

Question 13

What are the 5 major classes of antibody

Answer 13

IgM, IgG, IgD, IgE, IgA

Question 14

Where are the differences in the isotypes of antibodies

Answer 14

in the constant region

Question 15

Antibodies from the daughter cell have…..

Answer 15

different isotypes, but only one specificity

Question 16

Characteristics of IgM

Answer 16

pentamer, 10 binding sites, high avidity, first Ab produced in immune response

Question 17

Where is IgM found

Answer 17

serum and lymph

Question 18

What is the first antibody produced

Answer 18

Igm

Question 19

What does IgM do

Answer 19

Activate complement

Question 20

How many binding sites does IgM have

Answer 20

10

Question 21

How many binding sites does IgG have

Answer 21

2

Question 22

Where is IgG found

Answer 22

Serum, lymph, and tissue

Question 23

What is valence

Answer 23

how many binding sites on Ab are available

Question 24

What is the valence of IgG

Answer 24

2

Question 25

What is the valence of IgD

Answer 25

2

Question 26

Where is IgD found

Answer 26

Surface of B-cells

Question 27

What is the valence of IgE

Answer 27

2

Question 28

Where is IgE found

Answer 28

mucosa (bound to mast cells and basophils)

Question 29

What is the function of IgE

Answer 29

allergic reactions, response against helminthes

Question 30

What is the most common form of IgA

Answer 30

dimer

Question 31

What is the valence of IgA

Answer 31

4 (dimer form)

Question 32

Where is IgA found

Answer 32

Mucosal surfaces and secretions (tears/milk) and serum

Question 33

What does the paratope do

Answer 33

gives the Ab specificity for just one epitope

Question 34

What is cross reactivity

Answer 34

Specific Ab recognizes a second similar epitope

Question 35

What is the disadvantage of cross reactivity

Answer 35

Autoimmunity and diagnostic tests

Question 36

What is and advantage of cross reactivity

Answer 36

Immunizations

Question 37

What kind of affinity does cross reactivity have

Answer 37

low affinity (epitope not optimal, but good enough)

Question 38

What is affinity

Answer 38

Binding strength between epitope and paratope

Question 39

What is avidity

Answer 39

The sum total binding strength of all paratopes combined (ex. low affinity IgM may bind stronger than high affinity IgG because more valences[branches] so IgM>IgG avidity sometimes)

Question 40

What does signaling B cell via B-cell receptor do

Answer 40

Divide, differentiate, and secrete Ab

Question 41

What does opsonization do to antigen

Answer 41

enhances phagocytosis by macrophages and PMN by Fc receptors

Question 42

What can Ab do to toxins/viruses

Answer 42

Inhibit effects of toxins/viruses by binding to it

Question 43

What does Ab do to complement

Answer 43

begins the complement cascade

Question 44

What does Ab do to mast cells and with what does it work with

Answer 44

Degranulates mast cells, special Fc receptors on mast cells preloaded with IgE (allergies)

Question 45

What are immunoglobulin

Answer 45

Antigen recognition molecule of B cell

Question 46

Antibodies are always part of what immune response

Answer 46

Active

Question 47

Immune complex formation is what

Answer 47

Aggregation of Ag. Can be good or bad