Cell Recognition and the Immune System Ch 5

Question 1

What do antigens or proteins on cells identify

Answer 1

whether its a pathogen, non- self cell, mutated cell or a toxin

Question 2

Pathogen

Answer 2

Microorganism that causes disease/harms to the body/ or produces an immune response

Question 3

Antigen

Answer 3

a glycoprotein found on cell surfaces that stimulate an immune response

Question 4

What creates antigenic variation

Answer 4

Mutation

Question 5

Give examples of non-specific Response

Answer 5

Phagocytosis, mucas and cilia, skin, HCL in stomach, blood clots, sweat and tears have lysozyme, non-harming bacteria= competition

Question 6

Describe how phagocytosis occurs

Answer 6

chemical products attract phagocytes
Phagocytes engulf pathogens
Vesicle (Phagosome) forms around pathogen
Vesicle lysosome fuses and enzyme lysozome hydrolyses cell membrane of pathogen.

Question 7

What type of cells are phagocytes and what are the made up of.

Answer 7

White blood cell, made up of cell-membrane which allows it to change shape

Question 8

Which is faster specific immune response, or non-specific

Answer 8

non-specific is faster but specific in longer lasting immunity

Question 9

What is the name of the cells that produce specific immune response and where are they produced

Answer 9

Lymphocytes, white blood cells, produced by stem cells in the bone marrow

Question 10

What two responses are there for specific immune response

Answer 10

Cell mediated (T-cells) and Anti Body Mediated Response/ Humoral Response (B-cells)

Question 11

When do T-cells respond

Answer 11

When antigens are on a body cell, (when the organisms own cell has been infected, or mutated)

Question 12

Describe the Cell- Mediated Response

Answer 12

Pathogens invade body cells and are taken in by phagocytosis.
Antigens are place on the cell membrane of the phagocyte and a helper T-cell with a specific complimentary shape attached.
Activated T-cell to clone producing memory cells, helper cell, and killer T-cell

Question 13

Describe the Mediated Response

Answer 13

Antibody on B-cell attaches to complimentary antigen.
Helper T-cell binds to antigen and stimulates B cell to clone.
Plasma and memory cells produced, plasma produce antibodies.

Question 14

Give a similarity and difference between Plasma and memory cell

Answer 14

They will both have the same antibody, but memory cell last for decades while plasma cells survive few days.

Question 15

Why are antibodies effective against specific pathogens

Answer 15

Antibody has a specific structure/3D shape/ tertiary structure.
Antigen has to have a complementary shape to bind and produce antigen-antibody complex

Question 16

Why does antibodies structure mean it will only detect certain pathogens

Answer 16

Variable region has specific amino acid sequence. The shape of the binding site will therefore only be complimentary to specific antigen.

Question 17

How would a log scale show if there is an exponential increase

Answer 17

An exponential curve becomes a straight line plot on a log scale

Question 18

How do vaccines work

Answer 18

inactive pathogens or antigens are (injected)
Phagocytes take up antigens,
T-cells attach and are activated to clone, helper T cell produce which activates B cell to clone, producing plasma and memory cells. Memory cells produces Secondary Response

Question 19

Why are people vaccinated more than once?

Answer 19

So more antigens are present producing more memory cells which will result in a quicker immune system

Question 20

Antibody

Answer 20

Y shaped protein made up of four polypetide chains

Question 21

How are monoclonal antibodies produced

Answer 21

Mouse is vaccinated with a disease. Plasma cells produce by mouse are taken and fused with tumour cells also produced from mouse, in order to ensure quick division/cloning. Producing many antibodies

Question 22

Give uses for monoclonal antibodies

Answer 22

Cancer treatment(attaches to cancer cells) and therapy (drug attached to antibody). Pregnancy Test

Question 23

How does a pregnancy test work?

Answer 23

HCG hormone binds to monoclonal antibody that is attached to a coloured particle, producing coloured line. The complex then binds to another antibody producing a second coloured line

Question 24

What is ELISA for

Answer 24

To detect the quantity of antigens in a solution

Question 25

Describe what happens in ELISA

Answer 25

Antibodies are immobalised and antigen same is added. Unbound antigens are washed away. A secondary antibody conjugate is added, then unbound ones are washed away. Coloured substrate is added.

Question 26

Give examples of Active natural and Active artificial immuntiy

Answer 26

AN= infected by pathogen, body produces immune response
AA = Vaccinated creating immune response

Question 27

Give examples of Passive Natural and Passive Artificial

Answer 27

PN= Antibodies are passed from mother to baby
PA= Injected with antibodies

Question 28

Vaccination

Answer 28

Induction of the antigen from appropriate disease, stimulating immune response and producing memory cells

Question 29

Herd Immunity

Answer 29

the percentage of the population that need to be vaccinated so that those that aren’t vaccinated would still not acquire it

Question 30

How does HIV replicate

Answer 30

Transmission through sex. Protein attachment binds to CD4 on Helper T-cells. Protein Capsid fuses with cell surface membrane.
HIV reverse transcription converts RNA to DNA. DNA moves into host cell and is inserted into hosts DNA. Cells enzymes starts to replicate DNA and divides producing new Virus particles.

Question 31

How does HIV lead AIDS

Answer 31

HIV attacks Helper T cells which are needed to co-ordinate immune response and stimulate B- cells. Lack of Helper T-cells means an insufficient immune response and disease develops

Question 32

Why don’t antibiotics work on HIV

Answer 32

Because it is a virus and doesn’t have all the organelles that antibiotics normally target, such as cell wall and ribosomes. Virus in host cells can’t be reached.