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41 Cards in this Set
- Front
- Back
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What are 6 uses of bacteria?
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RACPAD - rDNA, Antibiotics, Chemical Industry, Probiotics, Agricultural, Degradation of toxic waste
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How long are bacteria?
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1-6 Micrometers.
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How wide are bacteria?
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0.2-2.0 micrometers
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Cocci
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spheres
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Bacilli
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rod shaped
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Spirilla
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Spiral shaped
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Vibrios
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comma shaped
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Staph- prefix means....
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Clusters
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What do Prokaryotic cells lack?
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Nuclear membrane, straight chromosomes, multiple chromosomes, histones, organelle, sterols in membrane (except for Mycoplasma), triglyceride fats
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Ribosomes difference btw prok and euk
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Prok is 70s (50s + 30s). Euk is 80s (60s +40s).
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What are the three scientists that have improved the microscope?
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Janssen- combined two lenses. Kepler - improved. Leewenhoek - magnification of 50-300 diameters.
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Name the four types of light microscopes
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Dibs on Flips. Dark field, Brightfield, Flourescence, and Phase contrast. We use bright field compound microscopes in lab
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Electron Microscopes. magnification and name 4 kinds
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100,000x or 0.001 micrometers. TEM - Transmission electron microscope and SEM - Scanning electron microscope. 1,000,000x STM - Scanning tunneling microscope (uses probe with single atom tip ). AFM - Atomic force magnification (gives topographical image).
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Name parts on the cell envelope
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Semipermeable cell membrane. Cell wall - rigid. In gram neg - extra layer - outer membrane
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Cell membrane function
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regulates passage of molecules and ions. also provides rigidity for those who don't have cell walls (Mycoplasma)
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Mycoplasma
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have sterols and no cell wall. Causes atypical pneumonia
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Cell membrane structure
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Bilayer of 60-70% protein. 40-30% lipids.
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What is the main lipid in a cell membrane?
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phospholipid
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What are the differences in phospholipids btw bacteria and archea?
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Glycerol and fatty acids are linked by ESTERs in bacteria. Glycerol and isoprene chains are linked by Ether bonds.
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Intrinsic proteins
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Also called integral. make up 70-80% of membrane proteins. go through membrane
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Extrinsic proteins
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peripheral proteins. found on bilayer. some bind to intrinsic proteins.
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Transport through a cell membrane
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negative charge. passage depends on lipid solubility. large molecules are degraded by hydrolytic enzymes before transported though
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What does a cell wall do?
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Provides shape. barrier to env.
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What is a cell wall made of?
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peptidoglycan, a polysaccharide, linked by chemical bridges.
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Structure of cell wall
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two types of peptidoglycan: NAG is N-acetylglucosamine and NAM is N-acetylmuramic acid (NAM is only found in peptidoglycan). Linked to each other through beta 1,4 linkages.
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What are the four amino acids (tetrapeptide) attached to NAM?
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In gram -, L-alanine - D-glutaminate - Meso diaminopimelate and D-alanine. In gram +, L-lysine replaces diaminopimelate. Gram - = ala-glut-diaminopimelate-ala. Gram + = ala-glut-lys-ala
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What is the diff btw cell walls in gram + and -?
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Gram + have a pentaglycine bridge. 75% tetrapeptides are linked. 90% of cell wall is peptido. Gram - has 25% freq of linkage. 5-20% peptido
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Outer membrane
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only gram - have an outer membrane. phospholipid bilayer with LPS - lippolysaccharides that anchor to peptidoglycan layer and account for 40% of cell surface
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LPS components
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O-specific side chain. core polysaccharides (always the same), Lipid A portion
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O antigen
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polysaccharide that has 2,200 varients in Salmonella
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Lipid A portion
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glycophospholipid, toxic portion of gram - bacteria, responsible for fever and shock
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What are 3 ways bacteria will lack cell walls?
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1. mycoplasma 2. L forms - bacteria grown in presence of penicillin 3. Lysosyme hydrolyzes beta 1,4 bond destroying cell wall
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Periplasm
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(only in Gram -) the gap btw plasma membrane and outer membrane. Has many hydrolytic enzymes
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Capsules
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protects against phagocytosis. made of polysaccharide or glycoprotein.
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Pili
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Type 1 - attachment pili. Ex. Neisseria gonorrhoeae. F type - conjugatin pili
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What substances can only be found in bacteria?
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NAM and peptidoglycan
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What is a protoplast?
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Cell treated with lysozyme and sucrose so that it can be studied in a lab
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Run and Tumble
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Run - forward to food - flagella counterclockwise. Tumble - clockwise.
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Triclosan
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disinfectant. has high resistance among microbes
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Peptidoglycan Synthesis (simple)
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1. Building blocks gather in cytoplasm. 2. transfer through membrane to join existing cytoplasm
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Peptidoglycan Synthesis (descript)
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1. NAM and UDP = NAM-UDP + 5 aa. 2. attaches to bactoprenol-P to make NAM more hydrophobic for transport across membrane. 3. Complex is added to UDP-NAG by cross linking and through plasma membrane. 4. The new section adds by transglycosylation
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