Vocabulary- Bacteria (34 words)

Transcription

1 Biology II BACTERIA

2 Vocabulary- Bacteria (34 words) 1. Prokaryote 21. phototroph 2. Peptidoglycan 22. chemotroph 3. Methanogen 23. obligate anaerobe 4. Halophile 24. facultative anaerobe 5. Thermoacidophile 25. obligate aerobe 6. Bacillus 26. transformation 7. Coccus 27. conjugation 8. Spirillum 28. transduction 9. Streptococcus 29. pathology 10. Staphylococcus 30. exotoxin 11. Gram-negative bacterium 31. endotoxin 12. Gram-positive bacterium 32. antibiotic resistance 13. Antibiotic 33. zoonosis 14. Plasmid 34. bioremediation 15. Capsule 16. Glycocalyx 17. Pilus 18. Endospore 19. Heterotroph 20. autotroph

3 A. Prokaryotes I. Two Major Domains: Archaea and Bacteria a. Prokaryotes: single celled organisms that do NOT have a membranebound nucleus b. Live in any and all environments

4 c. Domain Archaea (archaea means ancient) 1. Very different than bacteria in their cell walls: do not have peptidoglycan (proteincarbohydrate compound in the cell wall), different amino acids in cell wall, different lipids in cell membrane 2. First thought to only be found in extreme locations (hot springs, swamps, etc ), now found in surface waters of oceans

5 3. Archaeal Groups a. Methanogens: get energy from converting hydrogen gas and CO 2 into methane gas 1. Live only in anaerobic environment (no oxygen) 2. Responsible for swamp gas and methane belched by cows b. Halophiles: archaea that live in environments high in salt content (Great Salt Lake and Dead Sea) c. Thermoacidophiles: archaea that live in very acidic environments that have high temperatures (hot springs) 1. The base of food webs in many communities

6 d. Domain Bacteria 1. Most known prokaryotes are bacteria 2. Three basic shapes: a. bacilli- rod shaped b. spirilla- spiral shaped c. cocci- sphere shaped 1. streptococci- chains of cocci 2. staphylococci- cluster of cocci

7 3. Gram Stain a. Most bacteria grouped according to the lab stain reaction 1. gram-negative bacteria: small amounts of peptidoglycanreddish pink color 2. gram-positive bacteria: more peptidoglycan- purple color

8 4. Important Bacterial Groups a. Proteobacteria 1. Largest and most diverse group 2. Many live symbiotically with other organisms (ex. Nitrogen fixing bacteria) 3. Some cause disease (ex. Rocky Mountain Spotted Fever) 4. Some live in humans and animal intestines (ex. E.coli)

9 b. Gram-Positive Bacteria 1. Not all members of this group are gram-positive 2. Strep throat, bacteria for Botox, yogurt making bacteria, antibiotic making bacteria found in this group

10 C. Cyanobacteria- use photosynthesis to get energy- produce oxygen d. Spirochetes- gram-negative bacteria that move in a corkscrew rotation- some cause syphilis and Lyme disease e. Chlamydia- gram-negative coccoid pathogens, only live inside animals

11 B. Biology of Prokaryotes 1. Structure and Function a. Cell Wall: gives the cell shape and protection b. Cell Membrane and Cytoplasm 1. cell membranes found just inside cell wall- lipid bilayer- regulate what comes in and out of the cell 2. do not have membrane bound organelles in cytoplasm c. DNA: found in a single closed loop attached at one end of cell membrane 1. plasmids: small, circular, selfreplicating loops of DNA- helps cause disease

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13 d. Capsules and Pili 1. capsule: outer covering of polysaccharides- protects against harsh conditions and white blood cells-helps stick to host cells 2. pili: short hair-like projections- help connect to each other for genetic exchange and to attach to host cells. e. Endospores: thick-coat that protects the DNA from harsh conditions

14 f. Prokaryotic Movement: most have flagella (long tails) 1. taxis: moving towards or away from a stimulus (chemotaxis- chemical is a stimulus) 2. Nutrition and Metobolism a. Prokaryotes need source of carbon and energy b. Heterotrophs: get their carbon from other sources c. Autotrophs: get their carbon directly from inorganic compounds 1. phototrophs: get energy from light 2. chemotrophs: get energy from chemicals

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16 3. Prokaryotic Habitats a. Prokaryotes live in certain habitats based on biochemical abilities b. Obligate anaerobes: cannot live where oxygen is present c. Facultative anaerobes: can live with or without oxygen d. Obligate aerobes: need oxygen (ex. TB) e. Temperature and ph also determine bacterial growth

17 4. Reproduction and Recombination a. Prokaryotes usually reproduce by binary fission (asexual reproduction) b. Recombination: exchanging DNA pieces with other prokaryotes without reproduction 1. transformation: takes DNA from outside environment 2. conjugation: prokaryotes bind together and one cell transfers DNA to another 3. transduction: a virus obtains a small piece of DNA and passes it onto other prokaryotes

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19 C. Bacteria and Humans 1. Bacteria and Health a. Pathology: the study of disease b. Pathogens: bacteria and other organisms that cause disease c. Toxins: poisons created by bacteria that cause disease 1. exotoxins: poisons secreted into the environment by bacteria (ex. tetanus) 2. endotoxins: poisons released once the cell dies (ex. E.coli) d. Bacteria can cause disease by destroying body tissues

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21 2. Antibiotics and Antibiotic Resistance a. Antibiotics affect bacteria by interfering with certain cellular activities (ex. Penicillin blocks the building of new cell wall) b. Antibiotics are made naturally by some fungi and bacteria to stop competitors 1. broad-spectrum antibiotics can kill more than one kind of organism

22 c. Antibiotic resistance: the evolution of populations of pathogenic bacteria that antibiotics are unable to kill 1. Caused by misuse of doctors and patients not finishing prescriptions

23 3. Emerging Infectious Diseases Caused by Bacteria a. Zoonosis: a disease that passes from animal to humans (ex. Lyme disease and ticks) 4. Food Hygiene and Bacteria a. Foodborne illnesses can be a major public health hazard b. Restrictions are put on restaurants to help prevent an outbreak

24 5. Bacteria in Industry a. Bacteria is used to make and process many common foods and important chemicals (ex. Yogurt, cheeses, and insulin) b. Bioremediation: a process where bacteria is used to recycle compounds (ex. Oil spills)