Disease Flashcards

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1
Q

outline 4 ways a pathogen is directly spread

A

physical contact, faecal, droplet infection, transmission via spores

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2
Q

state an way of indirect transmission in animals

A

vector via an animal

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3
Q

outline 4 social factors that can affect transmission of a pathogen

A

overcrowding, poor ventilation, poor health, migration

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4
Q

outline the process of indirect transmission for a plant

A

spores or bacteria will attach to insect then it will go to the plant

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5
Q

what pathogen causes tuberculosis and ring rot?

A

bacteria

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6
Q

what pathogen causes HIV/AIDS and influenza?

A

virus

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7
Q

what pathogen causes malaria, tomato late blight?

A

protoctista

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8
Q

what pathogen causes black Sigatoka, ring worm, athletes foot?

A

fungi

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9
Q

what are 7 physical plant defences ?

A

cellulose, lignin, waxy cuticle, bark, stomatal closure, callose, tylose

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10
Q

how does the cellulose cell wall act a physical and chemical barrier to pathogens?

A

it is a physical barrier and it releases certain chemicals when a pathogen is detected

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11
Q

how is lignin a physical defence?

A

it is waterproof to stop water bourne pathogens and is almost completely indigestable

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12
Q

how is the waxy cuticle a physical barrier?

A

prevents water collecting and entering cell surfaces so the absence of water prevents any pathogens

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13
Q

how is stomatal closure a physical defence?

A

will detect pathogens and close to stop them entering through air Bourne

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14
Q

what is the role of callose?

A

large polysaccaride deposit that blocks phloem seive tubes to stop a pathogen spreading

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15
Q

what is the role of tylose?

A

a balloon like swelling that fills and blocks xylem vessle to stop the spread of water that could contain pathogens. it also contains terpines(chemical) that are toxic to pathogens

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16
Q

what are 6 active defences of a plant ?

A

cellulose cell wall thickens with extra cellulose so becomes harder, deposition of callose, oxidative bursts, increase in production of a chemical, necrosis and canker

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17
Q

how does necrosis stop a pathogen?

A

cell suicide, by killing cells around infection it will stop the spread further around the plant, inniciated by injury apon a cell

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18
Q

how does Canker stop pathogen?

A

causes death of cambium tissue in the bark to stop the spread of pathogen

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19
Q

how do oxidative bursts stop pathogen ?

A

the burst produce highly reactive oxygen molecules that damage cells of invading pathogens

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20
Q

outline 5 chemical defences of a plant?

A

terpenoids, phenols, alkaloids, defensive proteins, hydrolytic enzymes

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21
Q

what are terpenoids?

A

essensial oils that are antibacterial and fungal

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22
Q

how do phenols stop pathogens?

A

antibacterial and fungal, tannins In the bark inhibit attack by insects which deactivates the salivary and digestive enzymes so they dies, therefore prevents transmission of pathogens

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23
Q

how do alkaloids stop pathogens ?

A

nitrogen containing compound which give a bitter taste to bark to inhibit herbivoirs from feeding on them

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24
Q

what are 3 hydrolytic enzymes and their function

A

chitinases - break down fungal cells
glucanases - hydrolyses glycosidic binds in glucans
lysosomes - degrade bacteria cell walls

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25
Q

what are 6 primary non specific defences in animals agains pathogens ?

A

skin, blood clotting, mucous membranes, inflammation, expulsive reflexes, wound repair

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26
Q

describe the process of blood clotting

A

following a break in the skin there is a cascade of events that leads to clotting. damage to blood vessel wall exposes collogen and releases clotting factors, platlets binds to collogen (release of clotting factors) which then cause the enzyme thrombokinase to activate, which( along with calcuim ions) converts prothrombin into active thrombin. Active thrombin converts soluble fibrinnogen into insoluble fibrin which attach to platlets in plug and form a mesh which traps red blood cells and platlets to form a clot.

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27
Q

describe the process of skin/ wound repair once a blood clot has formed

A

it will form a scab which shrinks as it drys drawing sides of the cut together so the skin can be repaired under the scab. collogen is deposited, stem cells divide to form new cells which migrate to edges and differenciate. new bllod vessels form to supply oxygen to new cells which contracts to draw edges in to complete the process.

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28
Q

describe the process of inflammation

A

mast cells detect if tissue is infected then release histamine which signals to other cells and causes vasodialation to let in fluid (containing WBC) into the tissue. this leads to increase in production of fluid to create swelling. This is drained into lymphatic system where it comes into contact with lymphocytes and this inniciates immune response

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29
Q

how is skin a primary non specific barrier to pathogens?

A

1st level of defence, and doesn’t target a specific pathogen. the epidermis have keratinocytes which migrate to surface then cytoplasm is replaced with keratin (keratinisation) these dead and hard cells are a barrier to pathogens

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30
Q

how is mucus membranes a primary non specific defence ?

A

will trap any pathogen on its own (without stimulation). epithelial layer will contain goblet cells which secrete mucus and extra mucus-secreting glands under. this traps pathogens, ciliated epithelium will waft mucus where it can be swallowed into stomach and killed

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31
Q

how do expulsive reflexes stop pathogens ?

A

when a pathogen is detected in an area prone to pathogens, they will cough, sneeze or vomit to expel the microorganisms out of the body

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32
Q

what is an antigen?

A

proteins or glycoproteins intrinsic to plasma membrane, how foreign cells are detected

33
Q

what are 3 phagocytes ?

A

netrophils, macrophages, dendritic

34
Q

how does structure of a neutrophil relate to its function?

A

has a multilobed nucleas due to flexibility, therefore it can get through capilaries and form cytoplasmic projections to engulf pathogens.

large number of lysomomes, in order to digest invading pathogens by phagocytosis.

receptor proteins on surface of plasma membrane to engulf pathogens into a phagosome

35
Q

how does a neutrophil detect a pathogen?

A

attracted to an area of infection by a response to a chemical (chemotaxis)

36
Q

explain what type of nucleas does a neurtrophil have?

A

lobed in order to squeeze through capillaries into tissue fluid

37
Q

outline the role of a neutrophil?

A

to engulf and digest pathogens

38
Q

how does a neutrophil digest a pathogen?

A

receptor proteins on plasma membrane attatch to antibody on pathogen, then its plasma membrane extends around pathogen engulfing it in a phagosome. A lysosome fuses with phagosome and then secretes digestive enzymes

39
Q

what is the structure of a macrophage?

A

large, long-lived cell. has a protein complex on surface of membrane called histocombatability complex

40
Q

what does the histocombatability complex do ?

A

ensures an antigen presenting cell is not mistaken for the pathogen

41
Q

what is the role of a macrophage?

A

they inniciate immune response, when it engulfs a pathogen it becomes an antigen presenting cell by presenting the pathogens antigens on the suface so that this can be recognised by lymphocytes and produce antibodies for the pathogen

42
Q

what is the difference in they way macrophages travel and settle?

A

travel as monocytes then settle in tissue where they mature into macrophages

43
Q

what is the role of the antigen presenting cell?

A

will move around the body to increase chance that it will come into contact with T and B lymphocytes that can activate the immune response (clonal selection ) and production of antibodies and memory cells

44
Q

where are dendritic cells found?

A

peripheral tissue

45
Q

what is the structure of a dentritic cell?

A

lengthy extensions of the cell to give high surface area to interact with pathogens

46
Q

what is the role of a denditic cell?

A

ingest then transport pathogens to lymphnodes

47
Q

what are 3 ways a pathogen can be presented during the specific immune response ?

A

macrophage engulfs it and becomes antigen-presenting cell,
infects a cell (virus),
or in body fluid

48
Q

explain what happens when the pathogen is engulfed by a macrophage?

A

APC releases monokines to attract neutrophil and stimulate b cells to differentiate into plasma cells to make antibodies

49
Q

explain what happens when the pathogen infects a host cell?

A

infected cell releases interferon which h stimulates release of Tkiller cells and get rid of pathogen in that cell

50
Q

what is the role of T helper cells?

A

release cytokines that stimulate the B cells to develop and stimulate phagocytosis

51
Q

what is the role of the T killer cells?

A

kill host cell that displays foreign antigen

52
Q

what is the role of the T memory cell?

A

provide long term immunity

53
Q

what is the role of the T regulator?

A

shut down immune response after pathogen is removed - prevents autoimmunity

54
Q

what is the role of plasma cells?

A

manufacture antibodies

55
Q

what is the role of Bmemory cells

A

remain in blood after infection and act as immunological memory

56
Q

what are the 3 types of cytokines?

A

monokine, interlukine and interferon

57
Q

how do cells communicate?

A

they relese cytokines that the target cell will have a completentory receptor to

58
Q

what is the role of monotones ?

A

released by macrophages to attract neutrophils and stimulate B cells to differentiate into plasma cells to release antibodies

59
Q

what is the role of a interlukines?

A

released by t cells and macrophages to stimulate clonal expansion and differenciation of B and T cells

60
Q

what is the role of interferon?

A

inhibits virus replication and stimulates activity of T killer cells

61
Q

what happens during clonal selection?

A

activation of T and B lymphocytes and production of antibodies and memory cells

62
Q

what is the role of Thelper cells with the APC in clonal selection ?

A

Th attach to APC receptors, interlukins are produced which activates the Th to divide by mitosis and clone themselves

63
Q

where are B-cells produced?

A

bone marrow

64
Q

where are T-cells produced ?

A

differenciates from B-cells in the Thymus

65
Q

what is an opsonin?

A

type of antibody that binds to a variety of pathogens, they enhance ability of phagositic cells to bind to them

66
Q

what is oppsonisation?

A

when an oppsonin will bind to antigen which will then bind to a phagocyte

67
Q

what is neutralisation in terms of oppsonaton ?

A

when the opsonin is bound to the antigen therefore the antigen is useless

68
Q

what is agglutination?

A

binds an antigen of one pathogen to the binding site of the antibody and then another antigen of a different yet identical pathogen to the same antibody. forms crosslinks between pathogens.

69
Q

what is an advantage of agglutination?

A

the pathogen is unable to physically carry out any functions because all antigens are neutralised
helpful with viruses - normally the cytoskeleton would have to drag a lysomome around the cell to engulf any viruses but if they are agglutinated then it will require less energy for the lysosome to engulf them therefore makes desroying viruses more efficient

70
Q

how many polypeptide chains is an antibodie made from?

A
  1. 2 light, 2 heavy
71
Q

what is the role of the hinge region?

A

allows the antibody to bind to another antigen, gives flexibility in order to bind to more than 1 antigen in agglutination but even in antigens art in right place the antibody can adapt its variable regions to fit

72
Q

what is the constant region?

A

area that has the same AA sequence across all antibodies

73
Q

where are antibodies produced?

A

plasma cells

74
Q

what is natural active immunity?

A

immunity provided by antibodies in the immune system as a result of an infection

75
Q

what is natural passive immunity?

A

antibodies provided by breast milk or placenta

76
Q

what is artificial passive immunity?

A

immunity provided by antibodies made by another iduvidual

77
Q

what is artificial active immunity?

A

immunity provided by immune system as a result of a vaccination

78
Q

what are 3 sources of new medicine ?

A

new diseases emerging, many diseases having no treatment, antibiotic treatments are becoming less effective