1. Antibodies can be found on the plasma membrane of ______________ (where they act as antigen receptors) or free in the extracellular fluid, where they are known as _________________________.
2. Antibodies consist of two types of polypeptide chains:
Two ______________ chains—located on the inside of the Y-shaped molecule
Two ______________ chains—located on the outside of the Y-shaped molecule
The chains are held together by ______________ bonds.
3. Each chain has a ______________ region that is unique for each antigen and a/an ______________ region that is the same for each antibody in a given class of antibodies.
4. Each arm of the Y-shaped antibody has identical _________________________ sites. The shape of these sites must match the shape of the _________________________ on the antigen in order to bind.
5. The stem of the Y-shaped antibody determines how it will interact with other components of the immune system. Complete the following examples given in this Topic:
Whether the antibody remains ______________ to the B cell
Whether it activates the _________________________ system
Whether it acts as a/an _________________________ to promote phagocytosis
Whether it can be joined with other antibodies to form a/an ______________ (pair) or _______________ (five antibodies)
Determines the ______________ pattern—how it travels through the body
6. Name the five classes of antibodies, each with a distinct type of stem:
1. _________________________
2. _________________________
3. _________________________
4. _________________________
5. _________________________
7. Complete the list of four contributions of IgG antibodies:
1. Constitutes the _________________________ of circulating antibodies
2. Formed in the late ______________ and throughout the ______________ immune response
3. Provides _________________________ to the fetus
4. Can be transferred from one individual to another (example of ______________________ immunity)
8. Match the characteristics listed below to the correct antibody. Choose either IgM or IgA.
These antibodies are found in secretions of tears, sweat, and saliva _____
First antibodies secreted in response to a new antigen _____
Retained as monomers on the surface of B cells _____
Found in the mucosa of the gastrointestinal tract _____
Found in breast milk _____
Secreted as pentamers _____
9. IgE is produced as a result of the body’s infestation with _________________________. Which white blood cell type is important to combat this infestation? ______________
List the two key factors in the production of IgE:
1. _________________________
2. _________________________
10. In modern, industrialized countries, the most common function of IgE is its role in _____________ responses. When exposed to an _______________ such as pollen, the body makes IgE antibodies.
11. The first exposure to an antigen is called _________________________. As a result, IgE antibodies are present on _____________ and _____________. During the second exposure, the allergen causes the release of _____________ and other inflammatory mediators.
12. As a result of the actions of the chemical released in question 11, the affected person gets a runny nose (due to _________________________) and has difficulty breathing (due to _________________________).
13. _________________________ are drugs that bind and block histamine receptors, thus alleviating the allergy symptoms.
14. Allergic reactions to peanuts can be very serious, causing a systemic allergic reaction known as _________________________.
15. IgD antibodies are located on the surface of _____________ cells and act as an antigen receptor. They participate in activating the _____________ cell.
16. There are four general ways that antibodies work (to remember: PLAN). Fill in the following:
1. P—act as opsonins to destroy pathogens by _____________
2. L—initiate complement activation, resulting in _____________ of the pathogen
3. A—cause _____________, the clumping of molecules, which enhances phagocytosis
4. N—cause _____________, which prevents toxins and viruses from interacting with body cells
17. List the three key points for B cell activation:
1. B cells respond to _____________ antigens.
2. These antigens are concentrated in the _________________________.
3. B and T cells continually _____________ and congregate in the _________________________ (where the antigens are concentrated).
18. When naïve B cells encounter their specific antigen (usually in the _____________ of the lymph node), the antigen is brought into the B cell by _____________. The peptide fragments of the antigen are displayed on the surface of the cell bound to _____________ proteins.
19. B cells then migrate deeper into the cortex, where T cells are found. In most cases, full activation of B cells requires the assistance of _____________ cells. These are known as “T cell-_____________ antigens.”
20. If the T cell recognizes the antigenic fragment bound to the _____________ protein on the B cell, the T cell binds to the B cell and _____________ are released from the T cell. The exchange of signals between the B and T cells is called _________________________.
21. _____________ cells are not needed for certain antigens such as polysaccharides. These antigens are known as “T cell-_____________ antigens.” These are generally (stronger or weaker) responses.
22. When the antigen has selected an appropriate B cell, the B cell will produce effector cells. Some B cells will move deeper into the _____________ and begin to secrete _______ antibodies, while others move to the germinal centers.
23. Name the three events (summarized below) that happen in the germinal centers to the offspring of the original, activated B cell:
1. _________________________; results in antibodies that are highly selective for the antigen
2. _________________________; results in the cells producing IgG, IgA, or IgE antibodies
3. _________________________; results in cells becoming plasma cells or memory cells
24. Humoral immunity can be acquired either actively or passively. Define each and give an example of the naturally and artificially acquired forms.
Active Immunity:
Naturally acquired:
Artificially acquired:
Passive Immunity:
Naturally acquired:
Artificially acquired:
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