Immune response Flashcards

Question

What is a monoclonal antibody?

Answer 1

Identical antibodies that have been produced by an immune cell that has been cloned from a parent cell

Answer 2

Y shaped proteins synthesised by B cells in response to foreign substances, such as viruses or bacteria

Answer 3

1. A specific B-Lymphocyte with complementary antibodies takes in surface antigens of a pathogen via endocytosis. 2. The B cell presents the foreign antigen on the cell membrane 3. Activated helper T cells will bind to presented antigens and trigger B cells to undergo mitosis 4. Some B cells will become plasma cells and secrete antibodies 5. Others will become memory cells which persist in blood plasma and tissue fluid and will rapidly divide into plasma cells upon reinfection

Answer 4

The production of antibodies by plasma cells and of memory cells

Answer 5

The rapid division and development of memory cells into plasma cells which make antibodies, and more memory cells upon reinfection

Answer 6

Secondary, because of the presence of memory cells

Answer 7

- In the cellular response, Helper T Cells are activated and undergo mitosis - In the humoral response, Helper T Cells activate B cells and the B cells undergoes mitosis.

Answer 8

4 chains, 2 heavy chains and 2 light chains

Answer 9

Disulphide bridges

Answer 10

Variable region is the binding site as it differs between antibodies Constant region is the rest of the antibody

Answer 11

Binds to an antigen to create an antibody antigen complex

Answer 12

Receptors on B cells

Answer 13

- Cause agglutination of bacterial cells, which makes it easier to for phagocytes to find as they’re less spread out through the body. - They serve as markers that stimulate phagocytes to engulf bacterial cells to which they’re attached

Answer 14

Agglutination is the clumping together of pathogens, making it easier for phagocytes to find. Agglutination is possible as each antibody has 2 binding sites and can attach to 2 bacterial cells, causing them to clump together.

Answer 15

- Production of monoclonal antibodies involves the use of mice, giving them a disease. It also involves deliberately giving mice cancer to produce tumour cells, which raises an ethical issue. - There have been some deaths associated with their use in the treatment of multiple sclerosis, Patients must give informed consent. - Drug trial involving monoclonal antibodies resulted in organ failure in volunteers.

Answer 16

Can be used for pregnancy tests, tests for diseases like HIV, cancer treatment, can be produced quickly.

Answer 17

Side effects are worse than anticipated, they’re expensive to produce.

Answer 18

1. Mouse is injected with an antigen to stimulate antibody production. 2. B cells are extracted from the mouse 3. These cells are fused with rapidly dividing tumour cells to form hybridomas 4. Hybridomas can produce many antibodies and divide rapidly.

Answer 19

1. Cancer cells have antigens called tumour markers 2. Monoclonal antibodies can be made that will bind to the tumour markers, and anti-cancer drugs can be attached to the antibodies 3. When antibodies come into contact with cancer cells, they’ll bind to the tumour markers 4. Meaning the drug will only accumulate around cancer cells. 5. They release chemicals that block signals that stimulate the uncontrolled growth of the cancer cells 6. Side effects are much lower because they accumulate near cancer cells

Answer 20

1. Application area contains antibodies for hCG, which are bound to a coloured bead 2. When urine is applied to the application area, any hCG will bind to the antibody with the beads 3. Forming an antibody-antigen complex 4. Urine moves up the stick to the test strip, carrying any bead with it 5. Test strip contains immobilised hCG antibodies 6. If there’s hCG present, the strip turns blue because the immobilised antibody will bind to the antibody antigen complex, saturating the strip with hCG antibody with the blue beads attached. If no hCG is present, the beads will pass without binding, so it won’t go blue.

Answer 21

Enzyme Linked Immunosorbent Assay

Answer 22

1. HIV antigen is bound to the bottom of a well in a well plate 2. A sample of the patient’s blood plasma is added to the well. HIV specific antibodies will bind to the antigen and remain at the bottom of the well 3. Well is washed out to remove unbound antibodies 4. Secondary antibodies with a specific enzyme attached are added to the well. These antibodies can bind to the HIV specific antibody. 5. The well is washed out again to remove and unbound secondary antibodies. 6. A solution containing a substrate which will bind to the enzyme and create a coloured product is added. If the solution changes colour, then HIV antibodies are present in the patient’s blood plasma, and they are infected with HIV.

Answer 23

Human Immunodeficiency Virus

Answer 24

Acquired Immune Deficiency Syndrome

Answer 25

Catalyses the production of DNA from RNA

Answer 26

Attachment Proteins Capsid Lipid envelope Viral RNA Reverse transcriptase

Answer 27

1. HIV uses attachment proteins to bind to complementary receptors on helper T cells. 2. Virus enters Helper T cells 3. Viral RNA and reverse transcriptase are released into the cell 4. Reverse transcriptase converts viral RNA to DNA 5. Newly made viral DNA moves into the nucleus of host cell and is inserted into host cell DNA 6. Viral DNA creates mRNA containing instructions to make new viral RNA, capsids and reverse transcriptase 7. Proteins are made using host ribosomes from viral mRNA 8. New virus particles are assembled 9. HIV particles burst out of host cell, breaking a piece of its cell surface membrane to make their lipid envelope

Answer 28

HIV attacks helper T cells. Without enough helper T cells, B cells can’t be activated to produce antibodies or cytotoxic T cells that kill antibodies. As a result, the body is more susceptible to secondary infections as the immune response is inadequate.

Answer 29

Antibiotics work by stopping bacteria from making cell walls by inhibiting the enzymes required for their synthesis. This weakens cells walls making them unable to withstand pressure. This way, when water enters by osmosis, bacterial cells burst and die.

Answer 30

Viruses rely on host cells to carry out metabolic activities, so antibiotics are ineffective as there’s no metabolic mechanisms or cell structures for them to disrupt.

Answer 31

The ability of an organism to resist infection.

Answer 32

Produced by the introduction of antibodies from an outside source.

Answer 33

The body isn't making its own antibodies so no memory cells are formed

Answer 34

Vaccination and exposure

Answer 35

Produced by stimulating the production of antibodies by the individuals own immune system, by infecting an individual with the disease

Answer 36

Results from becoming infected by a disease under normal circumstances. The body produces its own antibodies and may do so for years.

Answer 37

Forms the basis of vaccination. Inducing an immune response without suffering symptoms.

Answer 38

Vaccination is the introduction of the appropriate antigens/pathogens into the body in their dead or inactive form.

Answer 39

An immunity that arises when most or all of a population has been vaccinated meaning it is difficult for the disease to spread and highly unlikely that someone will encounter an infected individual

Answer 40

- Enough of the vaccine to immunise a large population - No/few side effects to avoid discouraging the population from being immunised - Means of producing, storing and transporting the vaccine - Effective way of administering the vaccine in large populations - All or most of the population must be vaccinated to achieve herd immunity

Answer 41

- Some people may have defective immune systems - If the disease is caught shortly after vaccination, the immune system won’t have built up resistance - Pathogen may mutate frequently, and the vaccine will become ineffective because. - Vaccines may be against 1 strain of a disease that has 100 strains - Some pathogens hide in body cells or body parts, concealed from the immune system - Individuals may refuse vaccination for medical, ethical, religious or daft reasons.

Answer 42

When pathogens mutate frequently and their antigens change. This means that immunity against disease is short lived because the body won't have antibodies against the new antigen

Answer 43

- Tested on animals - Testing on people can be tricky - Some people may not want to take the risk of side effects - Is it acceptable to trial with unknown health risks? - Should expensive vaccination programmes be continued when a disease is almost eradicated?

Immune response Flashcards

(68 cards)