Evolution of antibiotics Flashcards
(30 cards)
What is an antibody?
A protein produced by B cells that binds specific antigens.
What part of the antibody binds antigen?
The variable (Fv) region.
What determines the class (isotype) of an antibody?
The constant (Fc) region.
What cells produce antibodies?
B cells.
What does antibody neutralization achieve?
Blocks toxins and viruses from binding to cells.
What is opsonization?
Coating pathogens to enhance phagocytosis.
How does antibody activate complement?
By initiating the classical pathway.
What is the structure of an antibody?
Two heavy and two light chains forming a Y shape.
How is antibody diversity initially generated?
By V(D)J recombination.
What gene segments rearrange to form antibodies?
V, D, and J segments (heavy chain) and V and J segments (light chain).
How do heavy and light chains differ?
Heavy chains have D segments; light chains do not.
What is somatic hypermutation?
Deliberate mutation of antibody genes to improve binding.
What is affinity maturation?
The process of selecting B cells with higher affinity antibodies.
Where does affinity maturation occur?
In germinal centers of lymphoid organs.
How are B cells selected during a germinal center reaction?
By showing antigen to T cells and getting survival signals.
What happens to B cells that do not bind antigen well?
They undergo apoptosis.
What is an example of a second-hand antibody?
An antibody evolved for one antigen being adapted for another.
What role does Fc region play?
Determines the function and location of the antibody.
What is IgM specialized for?
Activates complement efficiently and forms pentamers.
What is IgG specialized for?
Efficient at opsonization and ADCC.
What is IgA specialized for?
Main mucosal antibody; resistant to enzymatic degradation.
What is IgE specialized for?
Important for fighting parasites and triggering allergies.
What is the function of IgD?
Acts as a receptor on naïve B cells.
How many classes of immunoglobulins exist?
IgG, IgA, IgM, IgD, and IgE.
