Viruses -Segments of RNA or DNA contained In a protein coat.
-
Upload
amanda-hawkins -
Category
Documents
-
view
218 -
download
0
Transcript of Viruses -Segments of RNA or DNA contained In a protein coat.
VirusesViruses-Segments of RNA or DNA -Segments of RNA or DNA contained In a protein coatcontained In a protein coat
Viruses are not living!!!Viruses are not living!!!
1) Viruses are not made of cells1) Viruses are not made of cells
2) Viruses do not grow2) Viruses do not grow
3) Viruses can’t reproduce on their own3) Viruses can’t reproduce on their own
2 Main Shapes of Viruses2 Main Shapes of Viruses
1) Helical Virus1) Helical Virus
- Rodlike- Rodlike
- Capsid proteins - Capsid proteins winding winding around core in a around core in a spiralspiral
2 Main Shapes of Viruses2 Main Shapes of Viruses
2) Polyhedral Virus2) Polyhedral Virus
-Many sides, roughly spherical-Many sides, roughly spherical
-Most efficient at holding viral genes-Most efficient at holding viral genes
BacteriophagesBacteriophages
Viruses that infect Viruses that infect bacteriabacteria
Structure is polyhedron Structure is polyhedron capsid w/ helical tailcapsid w/ helical tail
How can a Virus Reproduce?How can a Virus Reproduce?
Infect a living cellInfect a living cell
Living cell reads viral nucleic acids and Living cell reads viral nucleic acids and produces more virusesproduces more viruses
Bacteriophages go through the lytic or Bacteriophages go through the lytic or lysogenic cyclelysogenic cycle
Lytic CycleLytic Cycle
Viral genes are injected into the host cellViral genes are injected into the host cell
Host cell replicates viral genes and make viral Host cell replicates viral genes and make viral proteins (capsids)proteins (capsids)
Genes and viruses are put togetherGenes and viruses are put together
Process repeats until cell burstsProcess repeats until cell bursts
Lytic CycleLytic Cycle
http://student.ccbcmd.edu/courses/bio141/lecguihttp://student.ccbcmd.edu/courses/bio141/lecguide/unit3/viruses/lytlc.html#rellytde/unit3/viruses/lytlc.html#rellyt
Lysogenic CycleLysogenic Cycle
Viral gene is inserted into host chromosome Viral gene is inserted into host chromosome (provirus)(provirus)
When cell divides, provirus dividesWhen cell divides, provirus divides
Change in environment can begin lytic cycleChange in environment can begin lytic cycle
Lysogenic CycleLysogenic Cycle
http://student.ccbcmd.edu/courses/bio141/http://student.ccbcmd.edu/courses/bio141/lecguide/unit3/viruses/repmatly.htmllecguide/unit3/viruses/repmatly.html
http://www.youtube.com/watch?v=_J9-xKitsd0http://www.youtube.com/watch?v=_J9-xKitsd0
Emerging VirusesEmerging Viruses
Viruses that evolve in Viruses that evolve in geographically geographically isolated areas and isolated areas and are pathogenic to are pathogenic to humanshumans
Hanta VirusHanta Virus
Ebola VirusEbola Virus
Hantavirus Pulmonary SyndromeHantavirus Pulmonary Syndrome
May 1993May 1993
Acute respiratory Acute respiratory symptomssymptoms
Breathing in air Breathing in air contaminated w/ the contaminated w/ the virusvirus
Urine and fecesUrine and feces
Ebola VirusEbola Virus
19761976Severe, often fatal Severe, often fatal diseasediseaseFound in humans and Found in humans and non-human primatesnon-human primatesGabon, Sudan, the Ivory Gabon, Sudan, the Ivory Coast, Uganda, and the Coast, Uganda, and the Republic of the Congo.Republic of the Congo.http://www.cdc.gov/ncidohttp://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispd/dvrd/spb/mnpages/dispages/ebola/ebolatable.htages/ebola/ebolatable.htmm
Why do we encounter emerging Why do we encounter emerging viruses?viruses?
http://ffh.films.com/id/9505/The_Emerging_Virushttp://ffh.films.com/id/9505/The_Emerging_Viruses.htmles.html
PrionsPrions
Proteins and no nucleic acidsProteins and no nucleic acids
Cause disease by influencing how proteins Cause disease by influencing how proteins foldfold
Misfolding spreads like a chain reactionMisfolding spreads like a chain reaction
Mad Cow DiseaseMad Cow Disease
Creutzfeldt-Jakob diseaseCreutzfeldt-Jakob disease
BacteriaBacteria
http://video.google.com/videosearch?http://video.google.com/videosearch?hl=en&q=bacteria&safe=vss&um=1&ie=Uhl=en&q=bacteria&safe=vss&um=1&ie=UTF-8&sa=N&tab=wv#TF-8&sa=N&tab=wv#
What are Bacteria?What are Bacteria?
Single celled, prokaryotic organismsSingle celled, prokaryotic organisms1/10 the size of most eukaryotic cells1/10 the size of most eukaryotic cells
-http://www.cellsalive.com/howbig.htm-http://www.cellsalive.com/howbig.htmHave a single circular piece of DNAHave a single circular piece of DNAReproduce by Binary FissionReproduce by Binary FissionAnaerobic and aerobic processes (Euk are Anaerobic and aerobic processes (Euk are mostly aerobic)mostly aerobic)Flagella is simpleFlagella is simpleSome have piliSome have pili
PiliPilihttp://microbiologybytes.com/video/photosynthesis.htmlhttp://microbiologybytes.com/video/photosynthesis.html
Along with gel-like capsule, pili help bacteria Along with gel-like capsule, pili help bacteria adhere to surfacesadhere to surfaces
Enable Enable ConjugationConjugation-two organisms exchange -two organisms exchange genetic materialgenetic material
Cell WallsCell Walls
Most Bacteria have 2 types of cell wallsMost Bacteria have 2 types of cell walls
-Gram-negative-Gram-negative
-Gram-positive-Gram-positive
The 2 types differ in susceptability to The 2 types differ in susceptability to anti-anti-
bioticsbiotics
-Chemicals that interfere with life-Chemicals that interfere with life
processes in bacteriaprocesses in bacteria
Three Basic ShapesThree Basic Shapes
Bacillus (Bacillus (buh SIHL uhsbuh SIHL uhs))
-Rod shaped-Rod shaped
Coccus (Coccus (KAHK usKAHK us))
-Round shaped-Round shaped
Spirillium (Spirillium (spy RIHL uhmspy RIHL uhm))
-Spiral shaped-Spiral shaped
Aggregating BacteriaAggregating Bacteria
Strepto- form filamentsStrepto- form filaments
Staphylo- form clustersStaphylo- form clusters
How Bacteria Cause HarmHow Bacteria Cause Harm
Metabolize their hostMetabolize their host
Secrete chemical compoundsSecrete chemical compounds
Metabolizing their hostMetabolizing their hostAcneAcne
Propionibacterium acnesPropionibacterium acnes, grow in the oil glands of skin, grow in the oil glands of skin
Metabolize certain kind of oil produced by glandsMetabolize certain kind of oil produced by glands
Oil glands increase oil production during pubertyOil glands increase oil production during puberty
Food increases so bacteria population increasesFood increases so bacteria population increases
http://www.nlm.nih.gov/medlineplus/tutorials/acne/htm/http://www.nlm.nih.gov/medlineplus/tutorials/acne/htm/_no_50_no_0.htm_no_50_no_0.htm
MythsMyths
Metabolize their HostMetabolize their HostMycobacterium tuberculosisMycobacterium tuberculosis
Once one of most common causes of death (1.6 million in 2005)Once one of most common causes of death (1.6 million in 2005)
Incidence rates have stabalizedIncidence rates have stabalized
Contracted from inhaling droplets of moisture containing bacteriumContracted from inhaling droplets of moisture containing bacterium
Cough up sputum (saliva mixed w/ mucus or puss) and blood, chest Cough up sputum (saliva mixed w/ mucus or puss) and blood, chest pain, fever, fatigue, weight losspain, fever, fatigue, weight loss
Over one third of world population is infected (5-10% will become Over one third of world population is infected (5-10% will become sick)sick)
Secrete Chemical ToxinsSecrete Chemical Toxins
Staphylococcus aureusStaphylococcus aureusCauses most common food poisoningCauses most common food poisoning
Nausea, vomiting, diarrheaNausea, vomiting, diarrhea
Secrete Chemical ToxinsSecrete Chemical Toxins
Clostridium botulinumClostridium botulinumCauses botulismCauses botulism
From improperly heated canned foodFrom improperly heated canned food
Double vision and paralysisDouble vision and paralysis
May die because can’t breathMay die because can’t breath
1g would is potent enough to kill 1 million people1g would is potent enough to kill 1 million people
Relevance of BacteriaRelevance of Bacteria
Living with youLiving with you
FoodFood
AntibioticsAntibiotics
Living with YouLiving with You
Streptococcus pneumoniaeStreptococcus pneumoniae - present in - present in upper respiratory tract of half the upper respiratory tract of half the populationpopulation
E. coliE. coli - Present in small intestine. Aids in - Present in small intestine. Aids in digestiondigestion
Streptococcus aureusStreptococcus aureus - causes most - causes most common staph infections.common staph infections.
Found in Nose and on skinFound in Nose and on skin
FoodFood
Fermented foodFermented food
Pickles, buttermilk, cheese, saurkraut, Pickles, buttermilk, cheese, saurkraut, olives, vinegar, and sourdough breadolives, vinegar, and sourdough bread
AntibioticsAntibiotics
Can be naturally produced by fungus or Can be naturally produced by fungus or imitated chemicallyimitated chemicallyPenicilliumPenicillium was first used antibiotic was first used antibioticEither stop bacteria from multiplying Either stop bacteria from multiplying (bacteriostatic) or interferes with formation (bacteriostatic) or interferes with formation of cell wall or cell contents (bactericidal)of cell wall or cell contents (bactericidal)Over 100 types and most often perscribed Over 100 types and most often perscribed medicinemedicine