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Chapter 18 Monerans Cocci – round Bacilli – rod Spirilla – spiral

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1 Chapter 18 Monerans Cocci – round Bacilli – rod Spirilla – spiral
The Bacteria are organisms in this kingdom Bacteria are classified by their morphology and physiology. Bacteria are noted by their shape Examples Cocci – round Bacilli – rod Spirilla – spiral

2 other prefixes diplo – two strep – chain staph – bunches


4 Domains Archaea and Bacteria
Bacteria are are sometimes classified into two Kingdoms: Archaebacteria and Eubacteria Archaebacteria/Archaea– adapt to harsh conditions Ex- methanogens, halophiles, thermophiles

5 Methanogen They 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 Halophiles Halophiles 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 Thermophiles Thermophiles 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 kingdom Ex – Lyme's, Syphilis, Typhus, Leprosy, MERSA, TB, Yersinia Pestis, Tetanus, Botulism, Pneumonia, Chlamydia, Salmonella, Cholera

9 Yersinia Pestis This 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 photosynthesis chemoautotrophs – are nitrogen fixing bacteria Without 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

12 Nitrogen fixing bacteria

13 Structure of e coli bacterium
DNA – 1 chromosome Cytoplasm/Cell wall/ Cell Membrane Flagellum - locomotion Pili – helps attach to other bacteria Ribosomes- makes protein Capsule – surrounds, carb. layer protects plasmid – small ring of DNA, has genes

14 Endospore – if conditions are harmful this process encases DNA and some cytoplasm, the bacteria will lay dormant Harmful conditions - dry 250 F to kill the endospore

15 Bacterial Respiration
Obligate anaerobe – can’t survive with oxygen Obligate aerobe – needs oxygen Facultative anaerobes – can live with or with out oxygen Almost 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 fission DNA 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 bacterium Genetic diversity

19 Diseases caused by bacteria
Pathogens – disease causing Diseases are caused by Toxins – poisonous substances secreted, or left by dead bacteria disrupts metabolism Gram stain - a series of dyes that turn violet or red-pink according to the chemistry of the cell wall 2 types … a. endotoxins – gram -, red stain, more complex b. 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 notatum conquered syphilis, gangrene and tuberculosis inhibits bacteria enzymes Most comes from the soil

23 Importance of Bacteria 18-6
Fermentation processes, much as brewing, baking, cheese and butter manufacturing Using biotechnology techniques, bacteria can also be bioengineered for the production of therapeutic proteins, such as insulin, growth factors, or antibodies E. Coli that lives in the human large intestine synthesize vitamin B and release it for human use Microbial 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 microscope Most viruses that have been studied have a diameter between 10 and 300 nm Viruses are not in a Kingdom why ? Not living Viruses are classified by DNA or RNA

27 Bacteriophage Viruses are intracellular parasites
Must invade to live and cause harm Bacteriophage virus attacks bacteria Made of a protein coat and nucleic acid

28 How viruses are spread 1. 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, Norwalk 3. insect and animal bites …. Rabies, West Nile both can lead to encephalitis 4. blood contact …. HIV, Hepatitis B ( 400x more infectious than HIV) , Hepatitis C 5. 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 present Also 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 fight The term vaccine derives from Edward Jenner's 1796 use of the term cow pox (from the Latin vaccīn-us, from vacca cow), which, when administered to humans, 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.[1][2] Further experimentation demonstrated the efficacy of the procedure on an infant.[2] Since vaccination with cowpox was much safer than smallpox inoculation,[3] the latter, though still widely practiced in England, was banned in 1840.[4] 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.[1]

30 Virulent – cause the disease
Stages a virus may be in Virulent – cause the disease Temperate – virus doesn’t cause a disease immediately A 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 fluids Such as blood 3. Electrophoresis – separates fragments of large molecules ( like DNA - charge) based on electrical charge

32 Types of Viruses 1. DNA virus Poxvirus – small pox
Herpes virus – cold sore mono chicken pox 2. RNA virus Rhabdovirus – rabies flu , measles, cold 3. Retrovirus makes DNA from RNA using an enzyme called reverse transcriptase, makes a new virus HIV/ Leukemia

33 Lytic Cycle Means lyse or break Form of replication
Phage is a virus that infects bacteria

34 Step 1 virus attaches to the cell
Step 2 releases enzymes, weakens cell Step 3 injects DNA or RNA which takes over the cells DNA Step 4 uses the cells DNA to assemble new phages using protein synthesis Step 5 enzyme breaks cell wall, virus burst out

35 The lysogenic cycle integration 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 division Inactive, temperate till condition releases it into lytic cycle


37 Other infectious agent
Viroid has RNA no capsid ex plant pathogen transmitted by pollen and seed and by several insects or a kitchen knife Potato spindle tuber viroid

38 Prion has capsid no nucleic acid ex scrapie, kuru
mad cow

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