Fekin Immunity Flashcards
(18 cards)
Describe how bacteria are destroyed by phagocytes.
- phagocytes detect the bacterium, and creates a phagosome around the pathogen
- lysosymes migrate toward the phagosome and fuse creating a lysosome where they secrete lysozimes
- which hydrolyse the bacterium ✔️
Give two structures a bacterial cell may have that a white blood cell does not have.
Any 2 of the following
- Cell wall
- Flagella
- Capsule
- Genetic information
- Plasmid ✔️✔️
Describe how B-lymphocytes respond when they are stimulated by antigens. (4 marks)
- divide by mitosis
- produce plasma cells
- plasma cells make antibodies
- plasma cells make memory cells ✔️
Out of these there items, which is most likely to act as an antigen during a blood transfusion. Explain your answer:
- Glycoproteins (on cell surface membrane)
- Phospholipid (within plasma membrane)
- Haemoglobin (in cytoplasm)
Component: glycoprotein
Explanation: it’s in the cell surface membrane therefore it can be recognised externally by the immune system ✔️✔️
Ah influenza virus is monitored over 10 years, from years 1-8 the number of ppl infected steadily decreases. At year 9 the number of ppl infected spikes drastically. Suggest a reason why.
- virus mutates
* as a result the ppl are no longer immune therefore more ppl become infected ✔️
Describe how T lymphocytes recognise and respond to a virus.
- the t-lymphocytes have cell surface receptors which recognise foreign antigens
- as a response they create T-killer cells that combat the virus. ✔️
Describe how B lymphocytes respond to a virus.
- b-lymphocytes devise via mitosis and produce plasma cells that secrete antibodies
- which forces the virus to clump so more virus cells are engulfed at once. ✔️✔️
Describe how an inhibitor can be used in medicine to treat a virus.
- inhibitors prevent an active site from functioning properly meaning a virus with an inhibitor can’t bind to an epithelial cell
- meaning the virus can’t leave the hoast cell. ✔️✔️
Explain why a specific enzyme can’t bind to anything other than its substrate.
- enzymes have a specific tertiary structure
* that’s complimentary to its substrate ✔️✔️
Data was collected in an investigation and been plotted on a graph. There is only 5 points and they are quite varied in place and don’t show too much of a common trend. How would you join the dots?
• dot to dot because you cannot predict intermediate values. ✔️
A dose of MCP (a drug that increases the body’s production of antibodies) was given to some mice. The dose was calculated in g per Kg body mass. Explain why the dose was calculated per units mass.
• take in different masses of mice ✔️
Explain how antibodies were produced when injected with sheep red blood cells.
- the t-cells recognise the foreign antigen triggering mitosis.
- the cells differentiate into different types of T-cells
- plasma cells secrete antibodies ✔️
A newspaper suggested that data collected from a test testing a new drug for immunity on mice, shows that taking the drug will give ppl increased resistance to disease. Give 2 reasons why this conclusion may not be valid.
- Only used in mice, not humans
2. Not all diseases are cured by antibodies ✔️✔️
A mother who was infected with HIV had a baby, the baby tested positive with HIV yet the baby might not be infected with HIV, why?
•antibodies are passed from the mother to the child until 18 months after the child is born ✔️✔️
A control well is set up every time this test is used. This is treated in exactly the same way as the test wells, except that blood plasma is replaced by a salt solution.
Explain 2 purposes of a control well.
- Shows that only enzyme changes colour
2. Make sure the washing is effective ✔️✔️
Explain how a phagocyte responds to a pathogen.
- phagocyte attracted to pathogen via chemicals released by it✔️
- cell surface receptors on phagocyte attach to chemicals on the surface on the pathogen ✔️
- a phagosome forms around pathogen and lysosomes migrate toward phagosome✔️
- lysosomes secrete lysozymes into phagosome where they hydrolyse the pathogen ✔️
- the useful products are absorbed by the phagocyte ✔️
How do antibodies lead to the destruction of the antigen?
- Agglutination of bacteria cells, forcing cells to clump so more cells can be engulfed at once.
- serve as markers to stimulate phagocytes to engulf bacterial cells which are attached✔️✔️
Describe the structure of an antibody.
4 polypeptide chains, 2 heavy chains, 2 light chains, 2 antigen binding sites, 2 variable regions, constant region and disulphides bridges.
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