5.5 Antibodies

Question 1

What are antibodies

Answer 1

Proteins with specific binding sites synthesised by B cells

Question 2

What are antibodies made up of

Answer 2

Four polypeptide chains. THe chains of one pair are long and called Heavy chains, the other pair are shorter and known as Light chains.

Question 3

What is the variable region

Answer 3

The binding site of antibodies, as they are different for each antibody.

Question 4

What is the constant region

Answer 4

The rest of the angien

Question 5

How does the antibody lead to the destruction of the antigen

Answer 5

1. They cause agglutination of bacterial cells. Allowing phagocytes to locate them easier as they are less spread out inside the body
2. They then serve as markers that stimulate phagocytes to engulf the bacterial cells to which they are attached

Question 6

What is a monoclonal antibody

Answer 6

An antibody produced outside of the body that is from a single line of cells consisting of the same antibody

Question 7

What functions do monoclonal antibodies have in science

Answer 7

1. Targeting medication
2. Medical diagnosis
3. Pregnancy testing

Question 8

How are monoclonal antibodies used to target medication

Answer 8

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 the receptors on their cancer cells
3. They attach to the surface of their cancer cells and block the chemical signals that stimulate their uncontrolled growth

Question 9

How are monoclonal antibodies used in medical diagnosis

Answer 9

Men with prostate cancer produce more of a protein called PSA, by using a monoclonal antibody that interacts with this antigen, it is possible to obtain a measure of the level of PSA in a sample of blood

Question 10

How are monoclonal antibodies used in pregnancy testing

Answer 10

The placenta produces a hormone called hCG and this is found in the mothers urine. Monoclonal antibodies present on the test strip are linked to coloured particles. if hCG is present in the urine it binds to these antibodies. The hCG-Antibody-colour complex moves along the strip until it is trapped by another antibody, producing a coloured line

Question 11

What are some of the ethical problems with monoclonal antibody use

Answer 11

1. Production of monoclonal antibodies involves the use of mice. These mice are used to produce both antibodies and tumour cells. The production of tumour cells involves deliberately inducing cancer in mice
2. Monoclonal antibodies require informed consent
3. 7 people suffered full organ failure after trialling a new monoclonal antibody.