Recognition of Extracellular Proteins

Question 1

What is an epitope?

Answer 1

The part of an antigen that the combining site of an antibody binds to

Question 2

What is the difference between antibody and immunoglobulin?

Answer 2

Antibody is the functional name, immunoglobulin is the structural name

Question 3

What are the Fab and Fc regions of an antibody?

Answer 3

The Fab region is above the hinge (contains combining site to bind antigens) and the Fc region is below the hinge (binds to other immune cells)

Question 4

Why are IgG and IgA important?

Answer 4

. IgG is transferred across the placenta from mother to foetus during gestational period
. IgA is secreted by the mammary gland in milk, so provides immune protection to the gut of the infant

Question 5

What is IgE?

Answer 5

Involved in allergic responses

Question 6

What is IgD?

Answer 6

Antigen receptor on B-cells

Question 7

Why is IgM usually found in the bloodstream?

Answer 7

Too large to diffuse across blood vessel walls, except in areas of inflammation (where vessel wall permeability increases)

Question 8

Describe the appearance of plasma cells.

Answer 8

Round nucleus surrounded by heterochromatin clumps around the periphery (wheel with spokes or leopard spot pattern)

Question 9

Which cells are involved innate immunity and which cells are involved in adaptive immunity?

Answer 9

. Granulocytes and macrophages are involved in innate immunity. They are destructive but non-specific.
. Lymphocytes (T-cells and B-cells) are involved in adaptive immunity. They are very specific because they have many different variant with specific surface receptors