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82 Cards in this Set
- Front
- Back
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define disease |
A condition with a specific cause where part or all of the organism is prevented to perform normally and instead leads to functions performing less efficiently. |
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give example of infectious and comunicable diseases |
chlamidia, flu |
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give example of life style induced diseases |
cancer, heart attack |
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give example of degenerative diseases |
Alzheimers and arthiritis |
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give example of genetic disease |
cystic fibrosis, sickle cell anaemia |
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give example of deficiency disease |
Scurvy |
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define symptom |
Indication of disease that is picked up by patient |
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define sign |
indication of disease that is not necessarily picked up by patient but picked up by doctors |
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give reasons for life expectacy increasing from 1900 to now |
-antibiotics! -eductaion/research -screening -better welfare and health care available -surgeries -vaccine programmes |
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define infectious disease |
diseases caused by pathogens |
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what is a pathogen |
disease causing organism that invades host cell and causes harm |
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what are communicable diseases |
diseases that are infectious and can be passed from one person to another |
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describe kochs postulates |
-The pathogen must be present when the disease is present and be absent when the disease is absent. -should be able to isolate and grow in culture -should be able to transfer to new host, where disease should develop -should be able to isolate from new host |
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How pathogens can be transmitted |
-dropets in air(flu) -sexually(chlamydia) -direct contact with bodily fluids(Ebola) -water contaminated(cholera) -vector(malaria) -blood to blood(HIV,AIDS) |
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What is Aetiology |
the study and investigation of the cause and spread of disease |
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what is epidemiology |
The study of the patterns,causes, progression, effects on health and disease condition in a defined population |
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what is an epidemic |
-An outbreak of disease widespread across a community overtime |
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what is a pandemic |
an epidemic of the disease that spreads across continents and worldwide |
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What is a host |
Living cell where viruses reproduce |
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what is a resevouir |
animate or inanimate object/source which normally harbours disease. serve potential source of continous disease outbreak |
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what is a vector |
plant or animal that transmits the infectious agents from one host to another host |
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what is a carier |
Asymptomatic carier where an organism is infected but shows no symptoms and yet still pass it on |
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what is a virus |
A protein coated body that infects host cells to reproduce, thus harming host cells. |
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describe structure of virus |
viral genome contained in a nucleocapsid. Also in the nucleocapside are enzymes like reverse transcriptase for retroviruses. Then viral tengument makes up inner envelope. the envelope coats the whole virus. the envelope has envelope proteins and glycoproteins coated. |
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describe the variety of viruses |
-different genome, DNA,RNA -structures of capsid,helical or icosohedral different shapes, arrangement of capsomer -infect either bacteria, animals and so on |
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what is viral capsid made of and what is the purpose of the capsid |
capsomere protects genome and can aid attachment to hos |
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describe variety of viral genome |
-dna or rna -circular or linear -haploid or diploid -segmented or not segmented -single or double stranded |
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what is nucleic acid |
made up of phosphate group, ribose/dexyribose sugar and a base group. it forms the basic unit of genome |
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difference between dna and rna |
-rna single stranded and dna double -different pentose sugars -T and U -stay in nucleus leave nucleus |
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describe transcription in protein synthesis |
-helicase unwind specific part of DNA -mRNA form using DNA polymerase. -complementary base pairing occurs -a-u, c-g and t-a -mRNA leave nucleus by nuclear pore |
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describe translation in protein synthesis |
mRNA go to ribosome -attach to ribose, tRNA with anticodon binds to codon on mRNA. -on end of tRNA is amino acid -line of tRNA keep annealing to the mRNA. Amino acids form peptide bond -end codon stops the chain and polypeptide is transported to golgi body to by processed and packaged |
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how to DNA viruses replicate |
-bind to host cell -viral genome transcribed and replicated at nucleus -viral late genes expressed and viral capsid proteins made. -virus assemble in cytoplasm of host cell and leave cell, may take some antigen proteins from host membrane to avoid detection |
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how to RNA viruses replicate |
-virus bind to host cell -genome enters cytoplasm, RNA is translated to form capsid proteins and RNA is replicated by the enzymes produced from the translation -rna copied and capsid proteins formed. the virus develops and exit cell in mass numbers destroying it |
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How do retroviruses replicate |
-has rna reverse transcriptase enzyme in the capsid -genome and enzyme enter cell -RNA is converted into DNA/RNA Hybrid, the reverse transcriptase then forms DNA and integrease intergrated the DNA into the host genome -RNA viral genome that is expressed and at ribosomes forms capsid proteins, the virus then develops and leaves host cell, continuously producing the viruses |
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describe the structure of protein |
-primary; chain of amino acids -secondary; coil, h bond form -teritiary: 3d shape made of hbods, disulfide,ionic,hydrophillic and phobic -quaternary; polypeptides bind together |
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whats a prion and what is the infection |
-protein infection, normal prions bind with abnormal foreign prion to make protein plaques known as amyloid deposits that can't break down |
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describe structure of the bacteria |
nucleoid naked loop in cytoplasm. circular plasmid also in cytoplasm. enzymes and 70s ribosomes in cytoplasm. All surrounded by inner plasma membrane. Then peptidoglycan cell wall coats this. In gram negative, there is an outer membrane. Then the bacteria is coated in a capsule coated with pilli and some bacteria have flagella. |
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what is the difference between gram+ and gram- |
gram positive have thick cell wall and no outer plasma membrane. gram negative has a thin cell wall sandwiched between two plasma membranes |
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what domain is bacteria |
PROKARYOTES |
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what do bacteria have instead of mitochondria |
mesosomes |
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what are the shapes of bacteria under a microscope |
cocci-circular -staphylococcus(random circle) -streptococcus(chain of circle) -diplocoocus(pairs of cocci) bacilli-rods or chain of rods spirilla-spiral vibrio-c shaped |
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when growing bacteria in agar. how can you isolate one colony |
aeseptic technique |
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when isolating the colony, how can you identify the bacteria |
-colour of colony -shape of colony -opaqueness -elevation -margin -size |
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how do bacteria reproduce |
asexually. Binary fission |
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how does binary fission work |
1. cell elongate. DNA replicated 2. cell wall and blasma membrane divide 3. cross wall forms around dividing cells 4. separation |
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what is congugation |
bacteria can transfer genetic information to each other. Pilus becomes a bond. The plasmid unwinds, one section is transfered to recipient bacteria. then both bacteria have copy of the same gene(resistance) |
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describe the growth curve for bacteria |
-lag phase: The bacteria are adapting to environment, producing enzymes and starting to reproduce -log phase: rate of reproduction is greater than rate of death. The bacteria have excess nutrients and space -stationary phase: reproduction rate is = to death rate, space is limited, and waste build up. Secondary metabolites form(penicillum) -death phase; death over reproduction rate. very little space and nutrients |
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what factors afect bacterial growth |
-nutrients -oxygen -pH -temperature |
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what are the ways of measuring bacterial growth |
-turbidity -Haemocytomter -serial dilutions |
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How does turbidity work? |
The cloudiness of the solution determines the bacterial population. Colourimetry is used to determine how much light can pass. so giving density of solution |
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how to haemocytometer work |
The sample is placed into wells on a counting chamber. Under a microscope. the bacteria are counted on the grid. The top and left side are counted but not any touchin`g bottom and right |
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how to calculate number of bacteria |
-first calac volume of coverstrip= volume of large square squared then multiply the depth -count bacteria=19 -divide no. of bacteria by volume= 19/0.004=4750 -per cm cubed. so 4.75cm^3 |
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How does serial dilution work? |
Start with stock solution. have 9ml of broth in each solution. place 1ml of bacteria solution into the 9ml of broth and label this 1:10. or 1/10th. Then mix well and place 1ml of this into a second test tub also containing 9ml. mix that well and label 1:100 or 1/100th. keep going and create petri dishes of each until you can start counting colonies. |
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how to work out bacteria population from serial dilution |
number of colonies x reciprocal for dilution=number of bacteria/ml |
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which methods of measuring bacterial growth tells us total cell count |
-turbidity and haemocytomter |
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which method of measuring bacterial growth gives viable cell count |
serial dilution |
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what are the ways of controlling bacterial growth |
-heat -ionisation radiation -filtration -chemicals |
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whats an autoclave |
high pressure steam known as moist heat kill bacteria. used on equipment |
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what is heat used for bacterial control |
equipment |
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ionising radiation for bacterial control |
-beta rational and gama radiation -used for more effective sterilisation for hospital equipment and syringes |
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what is filtration used for in controling bacterial growth |
liquid samples -nitrocellulose sheet filter liquid, even viruses can't get through |
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what chemicals are used to control abcterial growth |
-disinfectants(don't kill bacterial spores, efected by temp,moisture,microbes population size) -antiseptics(bacteriocidal, bacteriostatics. do not kill spores) |
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how can you measure effectiveness of bacteriocidal |
-bioassay: zones of inhibition -phenol coeffecient test:compare effectiveness to phenol -use-dilution test:concentration used to kill 95% of microorganism. The lower the better, less toxic,cost and harm to environemt -dilution plate technique: uses agar plates |
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what is an antibiotic |
substance produced by microorganisms (fungi) which selectively supress growth or kill bacteria at low concentration |
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what are the ways antibiotics work |
-prevent cell wall synthesis -disrupt cell membranes -affecting nucleic acid or protein synthesis -affecting protein synthesis |
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how does cell wall synthesis distruption affect bacteria and which type of bacteria are unaffected |
-inhibits enzymes that build cross links in cell wall -gram negative unaffected as the have outer membrane |
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how do antibiotics distrupt cell membrane |
-polymyxin B bind to phospholipids of gram negative and make more leaky by interfering with function as selective bacteria |
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how is nucleic acid or proetin synthesis affected by antibiotics |
rifampin interferes with RNA synthesis in bactera by binding to subunit of RNA polymerase some antibiotics bind to ribosomes inhibiting protein synthesis |
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what mechanisms create resistance |
-enzymes break down antibiotics -capsule resistance -decreasing permeability of cell membranes |
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what 3 ways cause resistance |
mutation: allow it to be strongly adapted to environment transfer of genes:conjugation natural selection:not completing course of antibiotics |
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what are the types of fungal infections |
-skin mycoses -epithelial mycoses -systemic mycoses |
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what is the structure of a fungi spongiophore |
stolon with rhizoid roots. spongarium head with spores. columella under spores and apophysis just before columella |
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what is the general structure of fungus |
hyphae make up mycelium. chitin cell wall. |
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how to fungus reproduce |
both sexualy and asexually |
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what is a fungus |
eukaryotic organism that is either multicellular or single celled. Heterotrophic and have ergosterol instead of cholesterol. |
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what diseases come from epidermophyton fungi |
-athlete foot -ringworm |
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what is a parasite |
organism that lives in or on a host and exploits the host by getting nutrients at expence of host |
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what are the types of parasites |
-protazoan:plasmodium(malaria) -helminths(Tape worm) -ectoparasites(Lice) |
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whats a mechanical vector |
organism that the parasite doesn't require to survive. It doesn't fully depend on the vector for its life cycle |
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whats a obligatory host |
The parasite requires this host for its lifecycle. |
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whats an NTD |
neglected tropical disease, suffer lack of attention |
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what is genotype and phenotype |
Genotype is the alleles present and interaction of alleles and phenotype is the characteristics displayed from the genotype |
