Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CMOD- Block1 > Immunology 2: Antibody Structure > Flashcards

Immunology 2: Antibody Structure Flashcards

1
Q

What is an antibody?

A

the secreted effector molecules of B/plasma cells that bind to specific ligands on surfaces of pathogen; then serves as the ligand for phagocyte receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

All antibodies have a common core structure that consists of what?

A

2 identical light chains and 2 identical heavy chains; the heavy chains are attached to each other and each light chain is attached to a heavy chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an immunoglobulin domain?

A

a sequence of amino acids in an antibody sequence, about 110 residues long; can be either a variable and constant domain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The unique tertiary structure of antibodies enables them to do what?

A

withstand highly variable and potentially destabilizing extracellular conditions while maintaining functionality in the presence of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the primary difference between the structure of the C and V domains of immunoglobulin domains?

A

V domains are larger and have extra loops of polypeptide chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is common to the structures of both C and V Ig domains?

A

they are roughly cylindrical in shape; formed by 2 adjacent beta sheet structures linked by an intrachain disulfide bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is an immunoglobulin?

A

the antigen-binding molecule (effector molecule) of B cells; termed antibody once secreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The two identical heavy chains in an antibody monomer are joined together by ____ bonds.

A

disulfide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The V domains of heavy chains are adjacent to the V domains of light chains and form what?

A

the variable domains come together to form the unique antigen binding site of of each antibody molecule; this makes 2 antigen binding domains in each monomer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the significance of the carboxy terminus of the heavy chains of the antibody monomer?

A

they bind to antibody receptors, or Fc receptors, expressed on the surface of immune cells; this is one way the antibody bridges the innate and acquired immune systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Hypervariable regions of both heavy and light chain V domains are located alongside low variability regions known as ____.

A

Framework (FR) regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Framework regions of V domains form _____ that provide the structural framework of the domains while hypervariable sequences form _____ that correspond to the loops between beta sheets.

A

beta-sheets; loops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the complementarity-determining region?

A

this is the hypervariable site of a V domain within an antibody that serves as the antigen-binding site

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is an antigenic determinant, or epitope?

A

the portion of any particular antigen that an antibody binds to. Typically composed of glycoproteins, polysaccharides, glycolipids and proteoglycans.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a multivalent antigen?

A

pathogenic molecule that has more than one epitope and can be bound by multiple antibodies; these multiple epitopes can be repeating or distinct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Most antibodies have specificity for what types of chemical structures?

A

carbohydrates or proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Binding of antibodies to antigens is based solely on non-_____ forces.

A

based on non-covalent forces (electrostatic, van der Waals, H-bonding, hydrophobic interactions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What determines binding affinity of an antibody binding to its antigenic determinant?

A

the binding strength of the antibody to antigenic determinant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

To what does binding avidity refer?

A

the combined strength of all antigen binding domains of an antibody bound to its antigenic determinant simultaneously

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

A continuous epitope is formed by what?

A

a continuous, linear stretch of amino acids found on an antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

A discontinuous epitope is formed by what?

A

portions of an antigen that come together to form a discreet formation; ex: amino acids in a protein antigen are adjacent when the protein is in its native form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Antibodies can be divided into ____ different isotypes based on the type of ____ _____ that is found in the antibody.

A

5; heavy chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the hinge region of the heavy chain?

A

region of IgG, IgD, and IgA heavy chains that is rich in proline residues; allows flexibility of the antibody molecule in order that it may bind more easily to antigenic determinants or immune components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 5 types of heavy chains?

A

Ig A, D, E, G, M (greek letters though)

25
Q

What are the two types of light chains?

A

lambda and kappa

26
Q

What is the J chain and what is its function?

A

feature of multimeric IgA and IgM; 15kD polypeptide that is disulfide linked to the tail-pieces (C-term extensions of IgA and IgM heavy chains); functions to stabilize IgA and IgM multimers - these are the only antibodies that will form multimers

27
Q

CH2 Ig domain contains the determinant that ____ ____ binds to when initiating the classical complement cascade.

A

complement C1

28
Q

What functional region of antibody binds to complement proteins and Fc receptors on various WBCs, and consists only of heavy chain domains?

A

The Fc region/fragment (the bottom of the antibody Y shape)

29
Q

What is the Fab region/fragment of the antibody?

A

contains one antigen-binding site (each one half of the ‘V’ tops of the antibody Y shape)

30
Q

The beta barrel tertiary structure of light-chain C domains is stabilized by what?

A

a single interchain disulfide bond

31
Q

What separates the light chains C and V domains?

A

stretch of amino acids without secondary structure

32
Q

IgM is always secreted in ____ form, meaning it has how many antigen binding domains?

A

pentameric; 10

33
Q

IgA can be secreted in what form(s)?

A

monomeric, dimeric, or trimeric; most predominant/important is dimeric

34
Q

What is the primary function of IgA?

A

to neutralize pathogens and prevent them from colonizing mucosal surfaces

35
Q

Which Ig is the largest and why?

A

IgM, because it’s secreted as a pentamer

36
Q

Mast cells use which Ig as antigen-specific receptors?

A

IgE (this is the primary role of IgE)

37
Q

Which Ig(s) has the longest half-lives?

A

IgG subtypes

38
Q

What is neutralization?

A

preventing a pathogen/toxin from interacting with cell surface receptors which would facilitate colonization or entry into host cells

39
Q

Which Ig is actively transported into mucosal secretions to neutralize pathogens?

A

IgA

40
Q

IgG is actively transported across what barrier during pregnancy to passively protect the infant for several months after childbirth?

A

placenta

41
Q

What two Igs leave the vasculature to act in the extravascular space?

A

IgA (a little) and IgG

42
Q

Antibodies that have specificity for chemical structures other than carbohydrates and proteins are involved in what adverse event?

A

allergic reactions, autoimmune disease

43
Q

Would a monovalent antigen or multivalent antigen be more difficult for an antibody to bind?

A

monovalent, because basically there are fewer sites to recognize; the more and more different epitopes there are the easier for the immune system to recognize and bind the antigen

44
Q

T cell receptors only recognize antigens bound to what?

A

MHC molecules

45
Q

Would a monovalent antigen or multivalent antigen be more difficult for an antibody to bind?

A

monovalent, because basically there are fewer sites to recognize; the more and more different epitopes there are the easier for the immune system to recognize and bind the antigen

46
Q

Can an antibody molecule contain two different types of light or heavy chains?

A

No. The single, unique type of chain is what differentiates them.

47
Q

Which antibody type is most predominant in lymph?

A

IgG - it diffuses most into extravascular spaces, then is picked up by the lymph system

48
Q

Which Ab isotype is most involved in recognizing viral pathogens?

A

IgG - involved in sensitizing NK cells

49
Q

What are the different antibody isotypes (and number of subtypes) that can be secreted by plasma cells?

A

IgA (2), IgD, IgE, IgG (4), IgM

50
Q

Which antibody type is most predominant in lypmh?

A

IgG - it diffuses most into extravascular spaces, then is picked up by the lymph system

51
Q

Which antibody isotype has highest potential for binding avidity to its cognate antigenic determinant?

A

IgM - because it is a pentamer, all 10 can bind the determinant simultaneously

52
Q

Which antibody is responsible for anaphylactic hypersensitivity?

A

IgE

53
Q

Which antibody is responsible for protection against parasitic infection?

A

IgE

54
Q

Which antibody can most efficiently “fix” complement?

A

IgM

55
Q

Which antibody isotype has highest potential for binding avidity to its cognate antigenic determinant?

A

IgM - because it is a pentamer, all 10 can bind the determinant simultaneously

56
Q

Which portion (Fc, Fab) of antibody:antigen complexes can bind to complement, initiating the complement cascade?

A

Fc

57
Q

Which portion of antibody molecules can facilitate delivery of antibody to sites they would not reach without active transport? (sites include mucous, tears, milk, fetal blood circulation).

A

Fc portion

58
Q

Maternal isotypes of which antibody are responsible for keeping infants and young children well?

A

IgG - transported across placenta

IgA - transported via breast milk

CMOD- Block1 (36 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions