Cells - Cell recognition and the immune system - 3.2.4.5 - Monoclonal Antibodies

Question 1

What is an antibody?

Answer 1

A protein with a specific binding site.

Synthesised by B-lymphocytes (plasma cells)

Question 2

Identify the missing label.

Answer 2

Question 3

Identify the missing label.

Answer 3

Question 4

Identify the missing label.

Answer 4

Question 5

Identify the missing label.

Answer 5

Question 6

Identify the missing label.

Answer 6

Question 7

Identify the missing label.

Answer 7

Question 8

How many polypeptide chains make up an antibody?

Answer 8

4

Question 9

What does the antibody binding site bind to?

Answer 9

A complementary antigen

Question 10

What do we call an antibody that is bound to an antigen?

Answer 10

An antigen-antibody complex

Question 11

How does an antibody lead to the destruction of an antigen?

Answer 11

1. They cause agglutination of bacterial cells - clumping together to make it easier for a phagocyte to locate them.
2. They serve as markers that stimulate phagocytes to engulf the bacterial cells to which they’re attached.

Question 12

What is agglutination and how is it possible?

Answer 12

When an antibody binds to bacterial cells and causes them to clump together.

It is possible because antigens have 2 binding sites (see image).

Question 13

What is a monoclonal antibody?

Answer 13

An antibody produced by a single clone of cells.

Question 14

Give some uses of momoclonal antibodies.

Answer 14

• targetting medication to specific cell types
• medical diagnosis
• pregnancy testing

Question 15

Describe how monoclonal antibodies be used to treat cancer?

Answer 15

• produce monoclonal antibodies specific to the antigen on the cancer cell.
• give these to a patient and they will attach to the cancer cells.
• They will block the chemical signals that stimulate uncontrolled growth of cancer cells

Question 16

What is the name given to the monoclonal antibody treatment of breast cancer?

Answer 16

Herceptin

Question 17

Why are monoclonal antibodies better treaement in some cases than drugs?

Answer 17

Fewer side effects due to a very specific responce on target cells.

Question 18

Radioactive or cytotoxic drugs can be attached to monoclonal antibodies. How do these kill cancer cells?

Answer 18

The antibody with the attached drug attaches specifically to the cancer cell, and the drug kills the cell in a very targetted way.

Question 19

Monoclonal antibodies are used to test for HIV. What is the name of this test?

Answer 19

ELISA test

Question 20

When a woman is pregnant the placenta produces a hormone called chorionic gonadatrophin (hCG) that can be found in her urine. How can these hormones be used alongside monoclonal antibodies to diagnose pregnancy?

Answer 20

Monoclonal antibodies are linked to coloured particles on the test strip. If hCG is present in the urine it will bind to the antibodies on the strip, and cause the complex to move along the strip where it is trappd by another antibody careating a coloured line. No hCG no attachment - no line.

Question 21

What are the ethical issue related to the use of monoclonal antibodies?

Answer 21

• Mice are used to produce both tumour cells and monoclonal antiibodies. The use of animals in medical research nad treatment is an ethical isse as welfare is in quesiton.
• Although the use of monoclonal antibiodies saves many lives, there have been some deaths associated with their use (i.e. in the treatment of MS). It is important that patients are made fully aware of any potential risks.
• Accidents in medical trials involving human volunteers in which poeple are harmed cause a lack or truth in in industry and processes.