12.2 - Antibodies and immunity Flashcards Preview

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Flashcards in 12.2 - Antibodies and immunity Deck (29):
1

What are antibodies?

Soluble glycoprotein molecules

2

Where are antibodies produced?

Plasma cells (B lymphocytes)

3

What region is different in all antibodies?

Variable region

4

What are antibodies made up of?

4 polypeptide chains
Chain of sugar molecules attached to constant region
Heavy chain
Light chain
Variable region
Antigen binding sites
Receptor binding site

5

What methods are used by antibodies to destroy pathogens?

Agglutination
Precipitation of soluble antigens
Lysis --> antibodies bind and attract complement
Neutralisation of toxins
Opsonins

6

How does agglutination work?

Pathogens are immobilised when clumped together so prevents them from entering cells, making phagocytosis easier

7

What are complement?

A collection of proteins in the plasma which destroy the cell

8

Why may a blood test be carried out?

To establish if antibodies are present in the blood for several conditions
To establish if the patient has become infected

9

What test is done before giving a TB vaccine?

Mantoux test

10

What is a mantoux test?

Skin test for TB (tuberculin injection)

11

What do the results of a mantoux test indicate?

If inflammation occurs, they don't need the TB vaccine because they are already immune

12

What 2 types of HIV tests are there in the UK?

Point of care test

13

What do HIV tests look for?

HIV antibodies
p24 antigen

14

What is a point of care test?

Finger-prick test or mouth swab sample

15

What is a disadvantage of a point of care test?

There are issues with the sensitivity

16

What is the second method of detecting HIV?

Blood sample

17

What is an advantage of taking a blood sample?

More accurate
Less false positives/negatives

18

What is an advantage of a point of care test?

Find out the result almost immediately

19

What is a disadvantage of taking a blood sample?

Have to wait longer to find out the results

20

What is natural active immunity?

Immune response activates antibody production and memory cell production

21

What is artificial active immunity?

Vaccine of dead pathogen triggers immune response and encourages the production of antigens

22

What is natural passive immunity?

No antibody production by the person themselves
e.g. antibodies cross the placenta to the fetus

23

What is artificial passive immunity?

Antibodies are injected from another source
e.g. Tetanus immunoglobulin injections

24

What are allergens?

Antigens which trigger an (inflammatory) allergic reaction

25

Give examples of allergens

Pollen
Dust mites
Hair

26

Outline the stages of an allergic reaction

1) Initial contact with the allergen
2) Primary immune response triggered
3) IgE antibodies produced
4) Antibodies bind to receptors on mast cells
5) On the next encounter with allergen, allergen molecules bind to the IgE antibodies attached to the mast cell
6) Mast cell releases histamine
7) Inflammatory response is triggered

27

What is a mast cell?

A cell involved in the inflammatory response that releases histamine

28

What is a hypersensitive reaction?

Any undesirable reaction produced by the immune system

29

What type of reaction is an allergic reaction?

A hypersensitive reaction