Understanding the immune system P2 (L4) Flashcards
2 advantages of adaptive immune system
diversity
memory
What is immunological memory
ability to respond more quickly and effectively on a second encounter with an antigen
How is a lymphocyte activated
interaction between a antigen and a lymphocyte receptor
what cells does the principles of clonal selection apply to
B and T cells
What bonds are in the antibody
disulfide bonds
What determines the antibodys function
Fc domain
how is diversity obtained in antibody molecules
high amino acid variability in hyper variable regions
During a second encounter with an antigen what 2 things increase
amount of antibody
specificity of the antibody
what is affinity maturation
formation of higher affinity antibodies
How does affinity maturation occur
somatic hyper-mutation
What enzyme is used in somatic hyper-mutation
AID
What does enzyme AID do
converts cytosine to uridine
transition mutation
When is the only time somatic hyper-mutation occurs
secondary infection
4 main types of Fc regions (constant region)
IgM
IgG
IgE
IgA
3 types of mutation that can occur in affinity maturation
transition mutations
transversion mutation
gene conversion
What is the IgG antibody
high affinity antibody, key role in memory immune response
What is the structure of Ig antibody
2 heavy chains 1 light chains
What is the most common immunoglobulin in serum
IgG
Structure of IgM
Pentameric structure 5 antibody dimers held together by J chain protein
WHat type of antibody is IgM
Low affinity antibody, key role in protection
How many binding sites does IgM have
10
What is structure of IgA
dimeric structure, 2 antibody dimers held together by J chain
Where is IgA found
mucosal secretion (lots into intestine)
What is IgE structure similar to
IgG
