Presentation on theme: "Chapter 18 Monerans Cocci – round Bacilli – rod Spirilla – spiral"— Presentation transcript:
1 Chapter 18 Monerans Cocci – round Bacilli – rod Spirilla – spiral The Bacteria are organisms in this kingdomBacteria are classified by their morphology and physiology.Bacteria are noted by their shapeExamplesCocci – roundBacilli – rodSpirilla – spiral
2 other prefixesdiplo – twostrep – chainstaph – bunches
4 Domains Archaea and Bacteria Bacteria are are sometimes classified into two Kingdoms: Archaebacteria and EubacteriaArchaebacteria/Archaea– adapt to harsh conditionsEx- methanogens, halophiles, thermophiles
5 MethanogenThey are common in wetlands, where they are responsible for marsh gas, and in the guts of animals such as cows/sheep and humans, where they are responsible for the methane content of belching in ruminants and flatulence in humans.
6 HalophilesHalophiles can be found anywhere with a concentration of salt five times greater than the salt concentration of the ocean, such as the Great Salt Lake in Utah, Owens Lake in California, the Dead Sea
7 ThermophilesThermophiles thrive at relatively high temperatures, between 45 and 80 °C (113 and 176 °F)Hot springs of Yellowstone
8 Eubacteria/Bacteria - free living soil, water and some infect organisms and produce disease small in size, large kingdomEx – Lyme's, Syphilis, Typhus, Leprosy, MERSA, TB, Yersinia Pestis, Tetanus, Botulism, Pneumonia, Chlamydia, Salmonella, Cholera
9 Yersinia PestisThis bacterium can be transmitted to humans, usually by a vector such as fleas to lymph nodes that swell. In untreated people this may become dark or a black color. This type of plague is termed bubonic plague. The bacteria can spread into the bloodstream and eventually infect other organs.
11 Nutrition How do bacteria obtain their energy ? Heterotrophs – saphrophytes feed off the dead Autotrophs – photoautotrophs use photosynthesischemoautotrophs – are nitrogen fixing bacteriaWithout these saprophytic bacteria, the remains of dead organisms and plants would not decay .The bacteria also enrich the soil by returning these minerals to it, rendering it useful once again for plants and animals
13 Structure of e coli bacterium DNA – 1 chromosomeCytoplasm/Cell wall/ Cell MembraneFlagellum - locomotionPili – helps attach to other bacteriaRibosomes- makes proteinCapsule – surrounds, carb. layer protectsplasmid – small ring of DNA, has genes
14 Endospore – if conditions are harmful this process encases DNA and some cytoplasm, the bacteria will lay dormantHarmful conditions - dry250 F to kill the endospore
15 Bacterial Respiration Obligate anaerobe – can’t survive with oxygenObligate aerobe – needs oxygenFacultative anaerobes – can live with or with out oxygenAlmost all animals, most fungi, and several bacteria are obligate aerobes. Most anaerobic organisms are bacteria
16 Halitosis - is caused by anaerobic bacteria Halitosis - is caused by anaerobic bacteria. Known individually as anaerobes, these bacteria live in environments typically devoid of oxygen
17 Reproduction 18-5 Can occur every 15-20 minutes Asexual – Binary fissionDNA replicates, copies moves toward cell membrane, divide out evenly into two identical cells
18 Sexual reproduction conjugation Pili attach a portion of the DNA passes across the pili to the other bacteriumGenetic diversity
19 Diseases caused by bacteria Pathogens – disease causingDiseases are caused by Toxins – poisonous substances secreted, or left by dead bacteriadisrupts metabolismGram stain - a series of dyes that turn violet or red-pink according to the chemistry of the cell wall2 types …a. endotoxins – gram -, red stain, more complexb. exotoxins – most gram + , purple stain, secretes toxins, simpler
21 Gram – = endotoxin, protected peptidoglycans, more resistant to antibiotics
22 Antibiotics - Alexander Fleming 1929 mold fungus penicillium notatumconquered syphilis, gangrene and tuberculosisinhibits bacteria enzymesMost comes from the soil
23 Importance of Bacteria 18-6 Fermentation processes, much as brewing, baking, cheese and butter manufacturingUsing biotechnology techniques, bacteria can also be bioengineered for the production of therapeutic proteins, such as insulin, growth factors, or antibodiesE. Coli that lives in the human large intestine synthesize vitamin B and release it for human useMicrobial mining in which bacteria extract minerals such as copper
24 Hot Zone What do you remember ? Is ebola alive ?What does it look like ?What does it cause ?Where is it found ?
26 The Viruses Virus characteristics Viruses can’t be seen with the eye use an electron microscopeMost viruses that have been studied have a diameter between 10 and 300 nmViruses are not in a Kingdom why ? Not livingViruses are classified by DNA or RNA
27 Bacteriophage Viruses are intracellular parasites Must invade to live and cause harmBacteriophage virus attacks bacteriaMade of a protein coat and nucleic acid
28 How viruses are spread1. by air, dust or body fluids… mono, herpes, common cold, flu, SARS, measles, mumps, chicken pox, small pox (extinct), ebola ?2. contaminated food or drink …. Hepatitis A, Norwalk3. insect and animal bites …. Rabies, West Nile both can lead to encephalitis4. blood contact …. HIV, Hepatitis B ( 400x more infectious than HIV) , Hepatitis C5. Provirus have the virus but its a state that persists over longer periods of time as inactive
29 Also some antibiotics work on the cell wall of the organism. Viral diseases can not be treated with antibiotics because the enzymes they destroy are not presentAlso some antibiotics work on the cell wall of the organism.Others block protein synthesis by binding ribosomes.Viruses are merely nucleic acid (RNA and or DNA) and protein. Hence antibiotics are ineffective on viruses.Vaccines stimulate the immune system to fightThe term vaccine derives from Edward Jenner's 1796use of the term cow pox (from the Latin vaccīn-us,from vacca cow), which, when administered tohumans, provided them protection against smallpox.Sometime during the 1770s Edward Jenner heard a milkmaid boast that she would never have the often-fatal or disfiguring disease smallpox, because she had already had cowpox, which has a very mild effect in humans. In 1796, Jenner took pus from the hand of a milkmaid with cowpox, inoculated an 8-year-old boy with it, and six weeks later variolated the boy's arm with smallpox, afterwards observing that the boy did not catch smallpox. Further experimentation demonstrated the efficacy of the procedure on an infant. Since vaccination with cowpox was much safer than smallpox inoculation, the latter, though still widely practiced in England, was banned in 1840. Louis Pasteur generalized Jenner's idea by developing what he called a rabies vaccine, and in the nineteenth century vaccines were considered a matter of national prestige, and compulsory vaccination laws were passed.
30 Virulent – cause the disease Stages a virus may be inVirulent – cause the diseaseTemperate – virus doesn’t cause a disease immediatelyA virulent virus is one which is highly capable of causing severe disease while a temperate virus is one which would cause mild symptoms if any at all.
31 Methods of study 1. Tissue culture – grow cells, viruses 2. Serology – study of biological fluidsSuch as blood3. Electrophoresis – separates fragmentsof large molecules ( like DNA - charge)based on electrical charge
32 Types of Viruses 1. DNA virus Poxvirus – small pox Herpes virus – cold soremonochicken pox2. RNA virus Rhabdovirus – rabiesflu , measles, cold3. Retrovirus makes DNA from RNA using an enzyme called reverse transcriptase, makes a new virusHIV/ Leukemia
33 Lytic Cycle Means lyse or break Form of replication Phage is a virus thatinfects bacteria
34 Step 1 virus attaches to the cell Step 2 releases enzymes, weakens cellStep 3 injects DNA or RNA which takes over the cells DNAStep 4 uses the cells DNA to assemble new phages using protein synthesisStep 5 enzyme breaks cell wall, virus burst out
35 The lysogenic cycleintegration of the bacteriophage DNA into the host bacterium's genome.The virus is called a prophage which can be transmitted to daughter cells at each subsequent cell divisionInactive, temperate till condition releases it into lytic cycle