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22 Cards in this Set
- Front
- Back
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Gram positive is purple. Why is this?
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Because the cell wall has a peptidogllycan layer on top of the plasma membrane. The gram-negative has a thinner peptidoglycan layer that is between the plasma membrane and outer membrane. The outer membrane has a carbohydrate portion of the lipopolysaccharide.
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Peptidoglycan
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A network of modified-sugar polymers cross-linked by short polypeptides.
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Capsule
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A sticky layer of polysaccharide or protein on the cell wall of many prokaryotes. Allows for adherence to substrate or other individuals in a colony.
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Fimbriae
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Protein appendages that allow bacteria to stick to their substrate.
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Half of prokaryotes are capable of directional movement, T or F?
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Flagella
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Taxis
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Movement toward or away from a stimulus in a heterogeneous environment.
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Nucleoid
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A region of cystoplasm that appears lighter than the surrounding cytoplasm.
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Three features of prokaryotes
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1. Small
2. Reproduce by binary fission 3. Short generation times. |
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N2 to NH3
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Nitrogen fixation.
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Heterocytes
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Carry out only nitrogen fixation.
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Biofilms
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Metabolic cooperation between different prokaryotic species often occurs in this surface-coating colonies.
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Extreme Halophiles
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Live in highly saline environments. Require environment that is substantially more than seawater (3.5% salinity).
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Extreme Thermophiles
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Thrive in hot environments as hot as 90 degrees C.
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Methanogens
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Live in moderate environment. Use Co2 to oxidize H2, releasing methane as a waste product. Live in swamps and marshes where there is not any 02. Example.
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Four clades
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1. Euryarchaeota- All known methanogens
2. Crenarchaeota- Most thermophilic speicies 3. Korarchaeota- Yellowstone 4. Nanoarcheota- Smallest known of any organism. |
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Unique features of archae
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1. No Peptidoglycan
2. Some branched hydrocarbons in membrane lipids. 3. Several types of RNA polymerase 4. Methionine initiator amino acid 5. Some histones present. |
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Proteobacteria
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Gram-negative, large and diverse clade. Photoautotrtops, chemoautotrops, heterotrophs. Anaerobic and aerobic. 5 groups
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What are five groups of proteobacteria?
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1. Alpha- Closely associated with eukaryotic hosts; mitochondria may have evolved from this through endosymbiosis.
2. Beta- Nitrogen recycling. 3. Gamma- produce sulfur as waste product Slamonella. Legioneers disease. E. Coli 4. Delta- Slime-secreting myxobacteria. 5. Epsilon- Pathogenic to humans or other animals. Campylobaceter, Helico pylori. |
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Chlamydias
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Parasites that surviving only within animals, feast on ATP. Gram Negative walls, Unusual in that they lack peptidoglycan.
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Spirochetes
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Free-living, but others are notorious pathogenic parasites. Syphillis, lyme disease.
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Cyanobacteria
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Photoautotrophs, only plantlike, oxygen-generating photosynthesis organisms.
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Gram-positive
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Diversity, soil, free-living, parasites. Cause TB and leprosy. Anthrax. Myocoplasmas- only bacteria known to lack cell walls.
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