5.5 Antibodies

Question 1

What are antibodies?

Answer 1

A protein produced by lymphocytes in response to the presence of the appropriate antigen.

Question 2

What are antibodies made up of?

Answer 2

4 polypeptide chains

Question 3

What are made up of an antibody?

Answer 3

1. light chain
2. heavy chain
3. constant region
4. variable region
5. receptor binding site
6. antigen binding site

Question 4

What is formed when an antigen binds to the antigen binding site?

Answer 4

Antigen-antibody complex

Question 5

What do antibodies do instead of destroying antigens directly?

Answer 5

They prepare the antigens for destruction

Question 6

How do antibodies help in the destruction of bacterial cells?

Answer 6

1. they cause agglutination (凝集) of bacterial cells
2. they then serve as markers that stimulate phagocytes to engulf the bacterial cells that they are attached

Question 7

Why do antibodies cause agglutination (凝集) of bacterial cells?

Answer 7

So clumps (團塊) of bacterial cells can be formed and it’s easier for phagocytes to locate them as they are less spread-out within the body.

Question 8

Why is agglutination possible?

Answer 8

Because antibodies have two antigen binding sites.

Question 9

What are monoclonal antibodies?

Answer 9

Antibodies that are produced by a single clone of cells.

Question 10

What can monoclonal antibodies used to do?

Answer 10

1. treat cancers
2. pregnancy test

Question 11

How can monoclonal antibodies treat cancer?

Answer 11

1. monoclonal antibodies are produced that are specific to antigens on cancer cells
2. these antibodies are given to patients and attached themselves to the receptors on their cancer cells
3. they attach to the surface of their cancer cells and block chemical signals that stimulate their uncontrolled growth

Question 12

What are the advantages of monoclonal antibodies?

Answer 12

1. fewer side effects
2. the antibodies are not toxic
3. the antibodies are highly specific

Question 13

What are the ethical issues of monoclonal antibodies?

Answer 13

1. production of monoclonal antibodies involves the use of mice
2. testing for the safety of new drugs presents certain dangers
3. some deaths are related with their use in treatment
4. informed consent (patients have to have the full knowledge of the risks and benefits of these drugs before giving permission for them to be use)