Cell Recognition and the Immune System Ch 5 Flashcards
What do antigens or proteins on cells identify
whether its a pathogen, non- self cell, mutated cell or a toxin
Pathogen
Microorganism that causes disease/harms to the body/ or produces an immune response
Antigen
a glycoprotein found on cell surfaces that stimulate an immune response
What creates antigenic variation
Mutation
Give examples of non-specific Response
Phagocytosis, mucas and cilia, skin, HCL in stomach, blood clots, sweat and tears have lysozyme, non-harming bacteria= competition
Describe how phagocytosis occurs
chemical products attract phagocytes
Phagocytes engulf pathogens
Vesicle (Phagosome) forms around pathogen
Vesicle lysosome fuses and enzyme lysozome hydrolyses cell membrane of pathogen.
What type of cells are phagocytes and what are the made up of.
White blood cell, made up of cell-membrane which allows it to change shape
Which is faster specific immune response, or non-specific
non-specific is faster but specific in longer lasting immunity
What is the name of the cells that produce specific immune response and where are they produced
Lymphocytes, white blood cells, produced by stem cells in the bone marrow
What two responses are there for specific immune response
Cell mediated (T-cells) and Anti Body Mediated Response/ Humoral Response (B-cells)
When do T-cells respond
When antigens are on a body cell, (when the organisms own cell has been infected, or mutated)
Describe the Cell- Mediated Response
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
Describe the Mediated Response
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.
Give a similarity and difference between Plasma and memory cell
They will both have the same antibody, but memory cell last for decades while plasma cells survive few days.
Why are antibodies effective against specific pathogens
Antibody has a specific structure/3D shape/ tertiary structure.
Antigen has to have a complementary shape to bind and produce antigen-antibody complex
Why does antibodies structure mean it will only detect certain pathogens
Variable region has specific amino acid sequence. The shape of the binding site will therefore only be complimentary to specific antigen.
How would a log scale show if there is an exponential increase
An exponential curve becomes a straight line plot on a log scale
How do vaccines work
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
Why are people vaccinated more than once?
So more antigens are present producing more memory cells which will result in a quicker immune system
Antibody
Y shaped protein made up of four polypetide chains
How are monoclonal antibodies produced
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
Give uses for monoclonal antibodies
Cancer treatment(attaches to cancer cells) and therapy (drug attached to antibody). Pregnancy Test
How does a pregnancy test work?
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
What is ELISA for
To detect the quantity of antigens in a solution
Describe what happens in ELISA
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.
Give examples of Active natural and Active artificial immuntiy
AN= infected by pathogen, body produces immune response AA = Vaccinated creating immune response
Give examples of Passive Natural and Passive Artificial
PN= Antibodies are passed from mother to baby PA= Injected with antibodies
Vaccination
Induction of the antigen from appropriate disease, stimulating immune response and producing memory cells
Herd Immunity
the percentage of the population that need to be vaccinated so that those that aren’t vaccinated would still not acquire it
How does HIV replicate
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.
How does HIV lead AIDS
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
Why don’t antibiotics work on HIV
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.
