3.2.4 IMMUNITY CELLS AT WORKRK

Proteins in the cell surface membrane which triggers an immune response

- pathogens
- toxins
- infected cells
- foreign cells

1)The phagocyte is attracted to chemicals released by the pathogen and moves along a concentration gradient

2)Receptors on the phagocyte bind to the pathogen.

3)​ The phagocyte engulfs the pathogen and surrounds it in a phagosome

4)Lysosomes move towards it and fuses into the phagosome

5) The lysosomes release lysozymes which hydrolyse the pathogen.

6)The cytoplasm absorbs the soluble products and presents antigens

1)The cell binds the pathogen with its receptor and engulfs it
2) Then it breaks it down and presents antigen on receptors
3) Helper T cell bind to it and stimulates B cell to clone.

- 4 polypeptide chains
- Two light and two heavy.
- Chains held by disulfide bridges
- Two Antigen binding sites
- Variable and constant regions

antibodies with same tertiary structure formed from same cloned b cells.

1)Naive b cell binds to pathogen via complementary receptors
2) Cell engulfs it and internalises it and presents it in a receptor
3) Helper t cell binds to it and releases chemicals that stimulate b cell to clone
4) B cell starts to clone itself
5) Cells then differentiate into plasma or memory cells.
6) If same pathogen comes again memory cells starts to clone itself and differentiate into memory and plasma cells.

1) Stimulate b cells
2) Activate cytotoxic t cells
3)Stimulates b cells to do phagocytosis
4) Become memory cells

1) Naive helper t cell binds to an APC which causes it to clone itself
2) These helper t cells now:
-Stimulates B cells to clone
- Activates cytotoxic t cells
- Stimulates phagocytosis

A form of acquired immunity in which the body produces its own antibodies against disease-causing antigens/pathogens

the short-term immunity that results from the introduction of antibodies from another person or animal.

- Natural
- Vaccine (Artificial)

- Natural (Maternal)
- Artificial

- RNA
- Reverse transcriptase
- attachment proteins
- capsid
- matrix
- lipid envelope

1) Attachment proteins binds to helper t cell
2) HIV protein capsid fuses with t cell and the RNA enters.
3) Reverse transcriptase converts RNA into DNA
4) DNA enters nucleus and becomes integrated in hosts DNA.
5) Cell starts to create viral mRNA which is translated to viral proteins
6) These then assemble HIV clones

- Uses to target medicine at specific type of cells like cancers.
- Used for medical diagnosis like PSA

-Production of monoclonal antibodies involves the use of mice, which involves deliberately inducing cancer in mice
-Drug trials can be very dangerous and have led to death.

Non-specific:
physical barriers
Phagocytosis
Enzymes in tears
Specific:
T cells
B cell

Agglutination: Clumps pathogens together
Precipitation: Makes soluble antigens insoluble so easier to kill
Neutralisation
Inflammation and signalling

1)Antigen coated at bottom of well
2)Add antibody with enzyme
3)Wash
4)Add substrate and measure colour

1) Antigen coated at bottom of well
2)Add antibody
3)Wash
4) Add antibody (with enzyme) complementary to 1st antibody
5)Wash
6)Add substrate and measure colour

1)Antibodies coated at bottom of well
2)Add antigen
3)Wash
4)Add antibody(with enzyme) complementary to antigen
5)Add substrate and measure colour