Flashcards
Set 2: Section 2 -> Cells
Cards in this deck (92)
- 1Examples of Specific Defense Mechanisms*cell mediated response in t-lymphocytes
*humoral (fluid) response in b-lymphocytes when release antibodies - 2Pathogen?disease causing organism
- 3How do pathogens cause harm?-invade and digest cell components => kills cell
-release toxins => symptoms - 4Why is infection rare in the fetus?-protected by mother + placenta
- 5How do lymphocytes recognise own body cells in the fetus?-lymphocytes collide with self-material
-some will have receptors complementary in shape to self-material => die or suppressed
=> remaining lymphocytes = those that are complementary in shape to non-self material - 6How do lymphocytes recognise own body cells in bone adults?-lymphocytes made in bone marrow initially encounter self-antigens
-any that show immune response undergo apoptosis before can differentiate into mature lymphocytes
=> will not appear in the blood - 7Phagocytosis: Step 1-phagocyte attracted to pathogen by CHEMOATTRACTANTS produce by pathogen or damaged body cells
- 8Phagocytosis: Step 2Phagocyte moves towards pathogen down a concentration gradient
- 9Phagocytosis: Step 3phagocytes binds to pathogen => forms a phagosome
- 10Phagocytosis: Step 4lysosomes in phagocyte moves towards the pathogen
- 11Phagocytosis: Step 5lysosomes release lysozyme enzymes that hydrolyse cell walls of pathogen
- 12Phagocytosis: Step 6products are absorbed by the phagocyte
- 13T-Lymphocytes?-white blood cells that produce specific and long-term immunity by responding to antigens
- 14Where do t-lymphocytes mature?in the thymus gland
- 15What type of response do t-lymphocytes provide? Why?-cell-mediated immunity
-only respond to antigens presented on body cells - 16Antigen-Presenting Cells?-Phagocytes present antigens of pathogen engulfed on own cell-surface
-body cells invaded by viruses present some of their antigens
-transplanted cells have different antigens
-cancer cells have different antigens - 17T-Lymphocyte response: Step 1-pathogen invades cell or taken up by phagocytes
- 18T-Lymphocyte response: Step 2phagocyte places antigens on own cell-surface membrane
- 19T-Lymphocyte response: Step 3Receptors on t-helper cells fit onto specific antigens => activates them to divide by mitosis
- 20The cloned t-helper cells....-develop into memory cells
-stimulate phagocytosis
-simulate b-lymphocytes to divide and produce antibodies
-cytotoxic t-cells -> produce perforin protein to make cell membrane permeable -> kills cell - 21B-lymphocytes?-specialised white blood cells that produce antibodies that are soluble in the blood and tissue fluid = humoral response
- 22B-lymphocytes: Step 1-B-lymphocyte with receptors complementary in shape to antigens of surface of pathogen, toxin, foreign cell or damaged body cell, taken up by B-lymphocyte through endocytosis
- 23B-lymphocyte: Step 2processes and present the antigen on its own cell surface
- 24B-lymphocyte: Step 3-t-cell attaches to these antigens
-activate the B-cell - 25B-lymphocyte: Step 4-B-cell divides by mitosis to produce plasma cells that release antibodies specific to the antigen
- 26B-lymphocyte: Step 5-antibodies attach to pathogens and destroy them (primary response)
-antibodies have a short life-span - 27B-lymphocyte: Step 6Some B-cells develop into memory cells ->provide future protection from same pathogen (secondary response
- 28How do memory cells provide long-term immunity?-circulate blood + tissue fluid in search of pathogen
-if find pathogen, divide rapidly by mitosis into plasma cells
-destroy pathogen by producing antibodies -> circulate again - 29Why does the secondary response usually mean we do not suffer from symptoms?-faster response -> no time lag
-antibodies released at higher concentrations and for longer time period
-> more effective at killing off pathogen - 30What are B-lymphocytes like after being stimulated to produce antibodies?-more RER to make antibodies
-Golgi body to help package antibodies
-more mitochondria -> more ATP needed to produce peptide bonds - 31Antibodies?proteins made by B-lymphocytes with specific bind sites (Quaternary structure)
- 32What does an antibody do?-reacts with antigen on surface of non-self material by binding to them
- 33Diagram for an antibody
- 34Antigen Structure?-made up of 4 polypeptide chains held together by disulphide bonds
-2 x heavy chains and 2 x light chains
-specific binding site that is complementary in shape to antigen => antigen-antibody complex
-each binding site different = variable region - 35Role of Antibodies: agglutination-pathogens clump together
-easier for phagocytes to locate then as less spread out in the body
-clumps of viruses cannot enter cells - 36Roles of Antibodies: Stimulate?-Stimulate phagocytosis of cells they are attached to
- 37Monochlonal Antibodies?Antibodies produced by genetically identical B-lymphocytes. Therefore produce same antibody specific to one antigen
- 38What will each antigen induce?-a different B-cell to multiply and form clones -> release specific antibodies
-allows you to make monochlonal antibodies specific to any antigen you like - 39Producing Monochlonal Antibodies: Step 1-inject mouse with specific antigen you desire to make a complementary antibody to
- 40Producing Monochlonal Antibodies: Step 2-mouse specific B-lymphocyte activated => divides by mitosis into plasma cells that release specific antibodies
- 41Producing Monochlonal Antibodies: Step 3-isolate B-lymphocytes from blood sample that are producing desire antibodies
- 42ELISA Test?-allows you to see if a patient has any antibodies specific to a pathogen -> allows diagnosis of disease
- 43ELISA Test: Step 1-antibodies to PSA bound in well test plates
- 44ELISA Test: Step 2-blood of patient is added
- 45ELISA Test: Step 3-washed with distilled water to get rid of extra PSA that has not attached to antibodies
- 46ELISA Test: Step 4-monochlonal antibody with enzyme attached is added; will only bind if PSA present
- 47ELISA Test: Step 5-well is washed to remove unbound enzymes
- 48ELISA Test: Step 6-colourless substrate for enzyme is added
-enzyme converts it to a coloured product if PSA is present - 49What hormone does the placenta produce if the woman is pregnant?hCG
- 50Pregnancy Test: Step 1urine containing hCG is added to the dipstick
- 51Pregnancy Test: Step 2-dipstick has hCG monochlonal antibodies with blue dye attached to them
- 52Pregnancy Test: Step 3-hCG from urine binds to the antibodies
- 53Pregnancy Test: Step 4-hCG-antibody-colour complex moves up the dipstick
- 54Pregnancy Test: Step 5-trapped by a row of monochlonal antibodies to hCG -> creates a blue line
- 55Pregnancy Test: Step 6-new row contains antibodies that do not bind to hCG -> if blue line is here it means the woman is not pregnant
- 56Ethical Issues with Monochlonal Antibodies: production involves the use of mice-can involve deliberately inducing cancer in the mice
- 57Ethical Issues with Monochlonal Antibodies: use for treatment of multiple sclerosis-some deaths have been associated with the treatment
-important patients have full knowledge of the risks before receiving treatment so can give informed consent - 58Ethical Issues with Monochlonal Antibodies: Uses in drug trials-can be dangerous for the volunteers
- 59Forms of Vaccines?-Inactive Pathogen
-toxoid
-single antigen - 60How many antigens does an inactive pathogen have?-multiple antigens
- 61How is the inactive pathogen obtained?-inactivated by heat, radiation + chemicals/antibodies
- 62How does the inactive pathogen cause immunity?-still has antigens on surface of pathogen so still produces an immune response
- 63Disadvantages of Using an Inactive Pathogen?-may not inactivate every pathogen -> develop illness
-toxins may be released => symptoms
-has to make multiple antibodies -> takes longer to develop immunity - 64What is a toxoid?-a treated toxin
- 65How many antigens does a toxoid carry?-a single antigen -> one antibody produced
- 66How can you obtain a single antigen?-isolate it
-one antibody produced - 67Ethical Issues with vaccines-animal testing
-risk of side effects
-decision of who gets vaccine in an epidemic
-testing on humans = risky - 68Heard Immunity?-many people are vaccinated so even unvaccinated are less likely to contract the disease
-important as impossible to vaccinate whole of pop - 69Why may a vaccine not work?-fails if defective immune system
-may develop disease before immunity is high enough -> reinfect others
-antigenic variability -> antigens no longer affected by the same antibodies
-too many variants *influenza
-pathogens can 'hide' from immune system inside cells - 70How do Vaccines create immunity?-antigens injected so induces an immune response
-means that memory cells are produced => long term immunity and production of antibodies before suffer from symptoms - 71Features of a Successful Vaccination Program: economically available-in quantities high enough to vaccinate the vulnerable in the pop
- 72Features of a Successful Vaccination Program: few side effects-or will discourage individuals from getting the vaccine
- 73Features of a Successful Vaccination Program: means of...-transporting, storing + producing the vaccine
-usually needs advance tech, sterile conditions and refrigerated transport - 74Features of a Successful Vaccination Program: means of administrating-at appropriate time
-needs trained staff at different centers throughout the pop - 75Features of a Successful Vaccination Program: possible to vaccinate the majority of the pop for...heard immunity
- 76What disease does the human immunodeficiency virus cause?-HIV/AIDS
- 77Retrovirus?-viruses with the ability to convert RNA to DNA
- 78How does the HIV virus replicate itself?-uses its genetic material to instruct the host cell to produce HIV proteins to make a new virus
- 79How does the virus infect the body and replicate: Step 1-HIV enters the blood and circulates around the immune system
- 80How does the virus infect the body and replicate: Step 2attachment proteins bind to protein CD4 on the surface of t-helper cells
- 81How does the virus infect the body and replicate: Step 3-protein capsid fuses with cell-surface membrane to release RNA into the cell
- 82How does the virus infect the body and replicate: Step 4-HIV reverse transciptase converts the virus RNA into DNA -> inserted into DNA of the t-helper cell
- 83How does the virus infect the body and replicate: Step 5-HIV DNA create mRNA using the cell's enzymes
-creates instructions for new viral proteins
-> protein syntheis - 84How does the virus infect the body and replicate: Step 6-cell bursts and go on to infect other t-cells
-HIV breaks away with a piece of t-helper cell's membrane -> makes capsid - 85How does HIV effect the immune system?-infects and kills t-helper cells (host cells)
-t-cells activate phagocytosis, cytotoxic cells and B-lymphocytes
-=> immune system is damaged - 86Latency Period?-HIV is inactive for many years -> no symptoms
-person is described as being HIV positive
-leads to AIDS when begin replicating - 87What does the survival time of the patient depend upon?-existing infections
-strain of HIV
-age
-access to healthcare - 88What shape is the HIV?spherical
- 89Diagram of HIV?
- 90Why do antibodies effect bacteria and not HIV?-kills bacterial enzymes used for metabolic reactions
-cannot do this to viruses as use human enzymes - 91What causes transmission of HIV?-sexual intercourse
-sharing of needles
-blood transfusions - 92—
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- A level Biology Flashcards on Set 2: Section 2 -> Cells, created by Jemima Glazin on 06/03/2017.
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- Jemima Glazin
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