communicable disease Flashcards
1
Q
what is meant by infectious disease?
A
pathogens spread between people
2
Q
what are bacteria?
A
- prokaryotic cells
- no membrane bound organelles or nucleus
3
Q
What are 3 bacterial diseases?
A
- ring rot
- TB
- bacterial meningitis
4
Q
What does ring rot do and what does it affect?
A
- damages leaves and tubers
- affects potatoes, aubergines and tomatoes
5
Q
what is tuberculosis do and what does it affect?
A
- suppresses the immune system and destroys lung tissue
- humans, cows and pigs
6
Q
what is bacterial meningitis?
A
- infection in the brain
- causes sepsis and sudden death
7
Q
what is a virus?
A
- non living as it requires a host cell to reproduce
- 50x smaller than bacteria
8
Q
what is TMV?
A
- infection in tobacco plants
- damages fruit, leaves and flowers
- causes stunted growth
9
Q
what is HIV?
A
- virus in humans that suppresses the immune system
- targets t cells
10
Q
what is influenza?
A
- affects ciliated epithelium
- leaves airways open for infection
- prevented with a vaccine
11
Q
what are protoctista?
A
- eukaryotic organisms with a variety of feeding methods
- protists that cause disease are parasites
- need a vector to transfer them
12
Q
what is potato blight?
A
- hyphae penetrate host cells
- destroys leaves and fruit
13
Q
what is malaria?
A
- parasite is plasmodium
- vector is female anopheles
- invades red blood cells and damages liver and brain
14
Q
what is a fungus?
A
- eukaryotic organism that cannot photosynthesise
- saprophytic
- parasitic
-stop plants photosynthesising so quickly kills plant
15
Q
what is black sigatoka?
A
- cells are digested
- leaves turn black
- controlled with fungicide
16
Q
what is athletes foot?
A
- form of ring worm
- grows in warm moist areas
- antifungal creams to treat
17
Q
what are plants physical defences against pathogens?
A
- cellulose cell wall and thick waxy cuticle are dfficult to penetrate
18
Q
what are plants chemical defences against pathogens?
A
- hydrolytic enzymes break down pathogen cell wall
- callose to break down pathogen cell wall
- defensins break down fungal and pacterial cell walls
- lignin to strengthen
19
Q
what are humans physical defences against pathogens?
A
skin
- commensal bacteria compete with harmful
- sebaceous glands secrete sebum containing fatty acids which lower pH and kill baceria
- fat dead cells so cannot penetrate
mucus
- traps pathogens
- wafted out by cilia
- secreted by goblet cells
stomach acid
- kills pathogens due to low pH
20
Q
what are some processes in the non specific immune system?
A
- blood clotting
- phagocytosis
- inflammation response
21
Q
what is the process of blood clotting?
A
- platelets move to site
- adhere to endothelium and collagen and become activated to form a platelet plug
- two substances are released:
thromboplastin- enzyme that catalyses prothrombin into thrombin
serotonin - contracts muscles around wound to close it - ca2+ is the cofactor that activates inactive prothrombin
- fibrinogen (soluble pplasma protein) is converted to insoluble fibrin molecules
- clot forms and dries into a scab
22
Q
what is the process of phagocytosis?
A
- pathogens produce chemicals that attract phagocytes
- recognised ans non self
- pathogen and phagocyte meet
- pseudopodia on phagocyte surround and ingest by endocytosis
- enclosed by a vacuole called phagosome
- lysosome fuses with vacuole to form a phagolysosome
- pathogen ins digested and excreted via exocytosis
23
Q
what is the inflammation response?
A
- mast cells release histamines and cytokines
- vasodilation occurs and increases blood flow so more WBC’s, antibodies and plasma reach infected tissue
- histamines make vessels more permeable so more plasma leaks and becomes tissue fluid which causes swelling
- cytokines attract phagocytes
- these destroy pathogens
24
Q
what happens after phagocytosis (specific response)?
A
- phagocytosis produces an APC(antigen presenting cell) from a macrophage
- travels to lymph nodes and lymphocytes respond
25
how do B lymphoctes respond?
- humoral response
- B cell has antigen receptors on its surface complementary to only one antigen
- clonal selection of correct B cell occurs due to T-helper cell
- releases interleukins to activate B cell
- clonal expansion causes them to divide by mitosis and differentiate into plasma cells which produce antibodies that are specific to antigen, and memory B cells which stay in the body ready to provide a secondary response
26
how do T lymphocytes respond?
- receptors have a similar structure to antibodies
- T helper cells release interleukins which increaser phagocytic activity and trigger B cells to divide
- T killer cells/cytotoxic T cells search for APC's and attach to antigens and release perforin which creates holes in cell surface membrane which trigger apoptosis
- T regulatory prevent cells from attacking non infected cells by shutting down immune system
27
what are antibodies?
globular proteins that bind to antigens
28
explain the delay between infection and antibody production
- clonal selection must take place to find the right receptors on B cells
- mitosis and differentiation of B cells into plasma cells must take place
- antibodies are proteins so protein synthesis will take time to occur
29
what are the functions of antibodies?
defense - prevents toxins or virus entering host cell
immobilise - attach to flagella
agglutination - causes antibody-antigen complexes to clump together to prevent reproduction
lysis - activate the complement system to destroy bacterial cells
oppsonisation - pathogens coat in antibodies for recognisation
antitoxins - neutralise toxins from bacteria
30
what is the secondary response?
- immunological memory
- memory B+T cells provide a faster response
31
why is secondary response faster than primary response?
- primary response involves clonal selection and expansion
- memory B + T cells are already present in secondary response so faster
32
What is an autoimmune disease?
abnormal immune response against tissues normally in the body due to the immune system no longer recognising 'self' antigens
33
3 examples of autoimmune disease
T1D - affects insulin secretion and is treated with injections
rheumatoid arthritis -joints in hands and feet
lupus - skin and major organs
34
what are the chemicals involvedin the immune system?
- complement
- interleukins
- opsonins
- cytokines
- interferons
35
What is complement?
- proteins in blood plasma
- disrupt bacterial cell membranes
- cause cell lysis
- complement cascade enhances ability to clear microbes from an organism
36
what are opsonins?
they bind to antigens on pathogens and assists binding to phagocytes
37
what are interleukins?
cytokine that participates in clonal selection, expansion and differentiation of immune cells
38
what are cytokines?
cell signalling molecules released by immune cells to help regulate the immune response
39
what are interefons?
- trigger t cells and signal immune system
- proteins that are part of your natural defence system
40
what is active immunity?
antigens triggering a specific immune reaction which produces antibodies and memory cells
41
example of active natural immunity
exposure
42
example of active artificial immunity
vaccination
43
what is passive immunity?
acquired without and immune response
- no antibodies or memory cells are produced
44
example of passive natural immunity
placenta/colostrum
45
example of passive artificial immunity
injections
46
where is penicillin sourced and what is it?
- mould on melons
- antibiotic
47
what is docetaxel and where is it found?
- yew trees
- treatment of breast cancer
48
what is aspirin and where is it found?
- painkiller and anti-inflammatory
- willow bark
49
what is digoxin and where is it found?
- heart drug for atrial fibrillation
- foxgloves
50
where are antibiotics usually found?
fungi
51
why will it become difficult to discover new drugs in the future?
-new drugs come from plants
- biodiversity is reducing as habitats are being destroyed for fuels
52
what do medicines derive from?
- plants
- microorganisms
53
what are antibiotics?
- drugs used to treat bacterial infections
- effective against prokaryotes and dont affect eukaryotic cells
54
what are the two types of antibiotic?
bactericidal - kills
bacteriostatic - slows growth
55
how does antibiotic resistance occur?
- in presence of antibiotics, bacteria with resistance to antibiotics are favourable
- they survive and pass on the mutation
- this gives rise to a population of antibiotic resistance
56
what are some ways that antibiotic resistance can come about?
- gene mutation
- change in base triplet code in DNA
57
how is antibiotic resistance prevented?
- complete course
- only use when needed
- infection control
58
what is synthetic biology?
- involves assembling an entire genome
- use new or existing sequences
59
what are pharmacogenetics?
- tailoring medical treatment to each person
- analyses genome and its response to drugs
60
how can an effective vaccine produce active immunity to a disease?
- injected with an attenuated/dead/weakened form of the antigen
- causes an immune response
- memory B and T cells are produced in clonal expansion
- they remain in the body and provide a faster response upon infection hence no symptoms
61
what are the two types of vaccination?
live attenuated - weakened version of pathogen
inactivated - killed
62
what are the cons of vaccinations?
antigens:
drift - small changes to structure
shift - major changes
conceal - hide in cells or coat of host proteins
cross breed - create new strains
63
what is herd immunity?
- vaccinate most people so the minority who arent vaccinated dont get ill
64
what is ring immunity?
- people who work with vulnerable are vaccinated so they dont pass it on
65
what is a vaccine?
a safe form of an antigen which provides an immune response
66
why are booster vaccines necessary?
- number of memory cells decreases over time
- booster repenishes memory cells for a faster immune repsonse
67
why hasnt a malaria vaccine been created?
- different strains of plasmodium keep occurring due to mutations
- new vaccine per new strain
- parasites can conceal in cells and so are only exposed for a short amount of time
68
suggest two ways frankincense contributes to defending the tree from pathogens
- prevents pathogens entering via the damaged bark
- aromatic compound is antibacterial
69
how do traditional remedies provide a strong argument for the conservation of biodiversity?
- plants have medical benefits
- medicines derive from plants
70
what bond is found in antibodies and what is its function?
disulfide bridges hold the light and heavy chains together
71
what are the adaptations of neutrophils?
- many lysosomes and hydrolytic enzymes to digest waste produced by pathogen engulfing
- multilobed nucleus and can change shape to aid movement
72
name two barrier defences which help prevent entry of pathogens in animals
skin and mucous membranes
73
name two chemical secretions which help prevent entry of pathogens in animals
lysozymes and stomach acid
74
what are the two methods of direct transmission of pathogens between animals?
droplets or direct contact
75
what are the two methods of indirect transmission of pathogens between animals?
vectors and ingestion of contaminated food and water
76
name three factors which can increase the chances of transmission of a communicable disease between animals
- malnutrition
- overcrowding
- weakened immune system
77
What are the two methods of indirect transmission of pathogens between plants?
vectors and soil contamination
78
name three factors which can increase the chances of transmission of a communicable disease between plants
- overcrowding
- mineral deficiency
- damp and warm conditions
79
state five ways farmers and growers control the transmission of a communicable disease between plants
- crop rotation
- thorough cleaning of equipment
- controlling insect vectors
- leaving more space or gaps between growing plants
- removing plant material from soil after harvesting
