5.5: Antibodies

Question 1

What is an antibody

Answer 1

Antibodies are proteins with a specific binding site that are synthesised by B-Cells.

Question 2

When are antibodies produced

Answer 2

Antibodies are produced when the body is infected by non-self (foreign) material.

Question 3

What happens when antibodies are produced

Answer 3

The antibody reacts with an antigen on the surface of the foreign material by binding to it.

The antibody binding sites are complementary to a specific antigen

Question 4

Variety of antibodies

Answer 4

The variety of antibodies is massive because they are made of protons - molecules that occur in an almost infinite number of structure.

Question 5

Structure of antibodies

Answer 5

They are made up of 4 polypeptide chains

The long chains are called heavy chains

The short chains are called light chains

Each antibody has a specific binding site that fits very precise onto a specific antigen to form an antibody-antigen complex.

The binding site is called a variable region because there are many different antibodies that can attach to different antigens, the rest of the antibody is called the constant region because it is attached to receptors on B-Cells

Question 6

How does an antibody LEAD to the destruction of an antigen

Answer 6

Antibodies do not destroy antigens, they rather prepare the antigen for destruction.

Antibodies do this in two ways:

1. Cause agglutination of bacterial cells. Clumps of cells are formed making them easier to be discovered by Phagocytes for phagocytosis to occur.
2. Serve as markers that stimulate phagocytes to engulf the bacterial cells to which they are attached

Question 7

What is a monoclonal antibody

Answer 7

A monoclonal antibody is any antibody that is prepared outside of the body.

Question 8

Uses of monoclonal antibodies

Answer 8

1. Targeting medicated to specific cell types
2. Medical diagnosis
3. Pregnancy testing

Question 9

Monoclonal antibodies and targeted medication (cancer treatment)

Answer 9

1. Monoclonal antibodies are produced that are specific to antigens on cancer cells
2. These antibodies are given to a patient and attach themselves to receptors on their cancer cells
3. They attach to the surface of the cancer cell and inhibit chemical signals to stimulate their uncontrollable cell growth

Question 10

Monoclonal antibodies and medical diagnosis (Prostate cancer)

Answer 10

1. Men with prostate cancer produce a prostate specific antigen that can be detected in the blood by using monoclonal antibodies

Question 11

Monoclonal antibodies and pregnancy testing

Answer 11

1. When a woman is pregnant they produced hCG
2. hCG is found in the womans urine, the hCG binds to antibodies on the testing strip
3. The testing strip antibodies are associated with coloured particles - if hCG is present they bind and cause a coloured line to be formed.

Question 12

Ethical use of Monoclonal antibodies

Answer 12

1. Production of monoclonal antibodies requires mice, and in treatment of cancer requires tumours to be forcibly developed
2. 6 people had multiple organ treatment
3. Informed consent of their use