Defence Against disease 2

Question 1

How do B lymphocytes defend the body ( vague)

Answer 1

Create humeral immunity

Dispatches antibodies in the bodies humours, fluids, blood and lymph

Question 2

Stages of B lymphocytes defending an attack

Answer 2

1) identify antigen from pathogen : bacterium, fungus, toxin or virus
2) pathogens bumps into complimentary B cell, the one with the correct antibodies and binds to it (clonal selection)
3) B cell is then activated by t helper causing the b cell to proliferate clone rapidly, forming many cells with the exact same antibodies.
4) effector cells mass produce antibodies (2k per sec) for 4/5 days
5) antigens move round the body binding to as many antigens as they can, neutralisation or agglutination stops damage until pathogens engulf
humoral immunity

Question 3

B lymphocytes maturing process

Answer 3

Mature fully in the bone marrow
Once mature they have unique antibodies on the membrane of each cell, up to 10k
Helper T cells help mature naive effector B cells by binding to them and releasing cytokines

Question 4

How do t lymphocytes defend the body ( vague)

Answer 4

Cellular immune response

Cause immflamuation, activate macrophages, regulate immune response, fire up other T cells

Question 5

Stages of how T cells defend the body, cell mediated immunity

Answer 5

1) in the non specific defence system macrophages engulf and digest pathogens and display their antigens on their cell surface (APC’s )
2) receptors on some of the 2 cells fit these antigens, they bind and release interleukin stimulating more 2 cells to divide by mitosis. they form clones of the activated t helper cell that all carry the right antigen to bind to a particular pathogen
3) cloned t cells may: differentiate into t memory cells, produce interleukins that stimulate phagocytosis produce interleukins that cause b cells to divide, stimulate the development of a clone of T killer cells that are specific for the presented antigen

Question 6

What are professional antigen presenting cells

Answer 6

Macrophages that engulf pathogens and display pathogens antigens on their cell surface

Question 7

What to regulatory T cells do

Answer 7

Release anti cytokines

Question 8

Clonal selection

Answer 8

Correct\complimentary helper T cell binds to antigen presenting cell
Interleukin is released

Question 9

Clonal expansion

Answer 9

Interleukin produced by helper T cells after binding to correct APC
This activates the B cells
Stimulates T cell replication, memory, killer, helper
The activated B cells divide by mitosis to give clones of plasma cells and b memory cells

Question 10

Simple immune response

Answer 10

Nature of Antigen encountered, colonial selection , colonial expansion, differentiation, action

Question 11

T helper cells

Answer 11

Bind to the surface antigens on APC’s

Produce interlinking , which as a type of cytokines

Question 12

Interleukins

Answer 12

Stimulate the acuity of B cells, which increases antibody production , stimulates production or other types of T cells, and attracts and stimulates macrophages to enter the area

Question 13

General Antibodies structure

Answer 13

Large proteins known as immunoglobulins
Specific shape that is complementary to a specific antigen
4 polypeptide chains held together with disulphides bridges
2 long identical chains called heavy chains
2 shorter identical chains called light chains

Question 14

Antibody structure relating to function

Answer 14

Variable region - area of specificity, to an antigen, due to amino acid sequence. Located at the top of the Y
Hinge region- found between the long chains and short chains, allows flexibility for attachment to more than 1 antigen. Joining point of the Y
Constant region- same on all antigens ( main part of the Y) allows attachment to phagocytes

Question 15

Ways in which antibodies defend the body

Answer 15

Antibody of antibody-antigen complex acts as an opison so complex is easily engulfed
Pathogens are neutralised, so they can no longer invade host cell
Antibodies act as agglutinins causing pathogens carrying antibody-antigen complexes clumped together
Antibodies can act as antitoxins

Question 16

Active immunity

Answer 16

Already exposed to the pathogen, so body already has memory cells.
Antibody production is quick
Vaccination = artificial active

Question 17

Passive immunity

Answer 17

Artificial passive - injection of antibodies
Natural passive, mother giving baby chloesterin full of antibodies
Offers protection for a month

Question 18

Autoimmune diseases

Answer 18

Disease where the immune system mistakenly identifies your own cells as “foreign” rather than “self”
There are no cures: treatments are, immunosuppressants that slow down the immune system

Question 19

What factors increase the risk of autoimmune diseases

Answer 19

Genetics
Obesity
Sex - women

Question 20

Types of autoimmune diseases

Answer 20

Diabetes type 1 - destruction of pancreatic cells
Rheumatoid arthritis- damage to joints
Lupus - inflammation to lining of organs

Question 21

What vaccines contain

Answer 21

Killed or inactivated bacteria and viruses
Attenuated (weakened) strains of live bacteria or viruses
Toxin molecules that have been altered or detoxified
Isolated antigens extracted from the pathogen
Genetically engineered antigens

Question 22

Process of vaccination

Answer 22

Small amounts of save antigen, known as the vaccine, are injected into the blood
Primary immune response is triggered by foreign antigens, body produces antibodies and memory cells as if you were infected with the live pathogen
If you come into contact with the real pathogen the secondary immune response is triggered

Question 23

How vaccination changes due to pandemics or epidemics

Answer 23

Mass vaccination to to the spread

Herd immunity once enough of the population is vaccinated

Question 24

Sources of medicine

Answer 24

Penicillin- mould and fungus (melons)
Docetaxel - yew trees
Aspirin - willow bark 
Prialt- snake venom 
Vancomycin- soil fungus 
Digoxin- fox gloves

Question 25

Synthetic biology

Answer 25

Use of genetic engineering
Uses bacteria as a biological factory
Populations of bacteria are modified to produce much needed drugs in larger quantities than we would ordinarily have access to

Question 26

Development of antibiotic resistance

Answer 26

Random mutation occurs that makes some bacteria slightly more resistant, bacteria pass this mutation on to daughter cells
Farmers in the US routinely adding antibiotics to animal feed.
this accelerates natural selection.
Over prescription/ not fishing prescribed course of antibiotics leads to antibiotic resistance
Means some antibiotics may become useless

Question 27

Use of antibiotics in 20th century

Answer 27

Large number of death were due to communicable diseases

Antibiotics interfere with the metabolism of bacteria without affecting human cells - selective toxicity

Question 28

How do cytokines stimulate B lymphocytes

Answer 28

Cytokines has specific shape, complemnartyu to receptor
Cytokines binds to receptor on cell surface membrane
This activates clonal expansion

Question 29

How does HIV take over the host cell

Answer 29

Viral DNA inserted into host nucleus
Viral RNA and mRNA transcribed
To code for viral proteins

Question 30

Humoral immunity

Answer 30

Body responds to antigens found outside cells e.g free floating pathogens

Question 31

Purpose of the constant reigon

Answer 31

Allows binding to phagocytes

Speed of production

Question 32

Role of memory cells

Answer 32

Memory cells recognise display complimentary antigens to the pathgoen, binding to it (clonal selection)
Memory cells undergo clonal expansion dividing by mitosis to produce clones which then differentiate into plasma cells that produce antibodies
Help destroy viruses before symptoms appear

Question 33

How HIV takes over host cell

Answer 33

Revrse transcriptase inserted into host nucleus which converts the RNA which has also been inserted to DNA
The viral DNA is transcribed to produce viral RNA which is then translated to produce viral proteins

Question 34

how phagocytes are able to pass into the tissue fluid

Answer 34

they have a : narrow nucleus, a flexible cell structure

histamines make capillary walls leaky allowing phagocytes to squeeze through more easily