Chapter 4 – Microbiology Answers – Flashcards
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| Bacteria used as insecticide |
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| Bacillus thuringensis |
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| Bacteria used in warfare causing 1. anthrax and 2. food poisening |
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| Bacillus anthracis and Clostridium botulinum |
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| 5 features of prokaryotes |
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| 1. one circular chromosome 2. no histones 3. no organelles 4. peptidoglycan cell walls 5. binary fission |
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| Bacillus |
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| rod shaped |
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| coccus |
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| spherical |
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| spirillum |
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| wave shaped |
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| vibrio |
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| curved rod |
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| spirochete |
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| corkscrew |
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| strepto |
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| chain |
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| staphyl |
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| cluster |
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| 8 cell |
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| sarcinae |
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| 2 examples of pleomorphic bacteria |
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| 1. Rhizobium 2. Corynebacterium |
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| adavtages of having small size (3) |
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| 1. accumulate nutrients quickly 2. metabolize quickly 3. grow quickly |
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| largest bacteria known |
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| Epulopiscium sp. |
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| What is glycocalyx made of? |
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| polysaccarhides |
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| 2 functions of glycocalyx |
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| 1. source of food under adverse conditions 2. absorbs water, prevents dehydration |
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| biofilm is associated with this type of glycocalyx |
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| slime layer |
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| why does a capsule increase pathogencity of bactuera? |
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| white blood cells cannot grab them, prevents phagocytosis |
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| 3 functions of cell wall |
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| rigidity, shape, prevents osmotic lysis |
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| Tetrapeptide side chaings hang from... |
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| NAM |
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| Peptide cross bridges do what |
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| link layers of PG together maintain integrety of cell wall |
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| # layers of PG in Gram + cell wall |
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| 10-12 |
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| Teichoic acids roles and composition |
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| present in gram + regulate movement of cations alcohol/glycerol and phosphate provide antigenic variation |
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| antigentic variation |
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| ability of distinguish between bacterial cells |
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| Gram negative cell wall |
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| thin layer of PG no teichoic acids outer membrane |
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| composition of outer membrane in gram neg |
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| LPS (lipopolysarcharide) -made of Lipid A and O polysaccharide |
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| Lipid A O polysaccharide |
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| endotoxin antigen, used for distinguishing bacteria |
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| example of a bacteria whose antigen identifies it |
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| E Coli O157:H7 |
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| how penecillan works |
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| kills PG in gram + bacteria, specifically by breaking peptide cross bridges |
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| acid fast cell wall composition |
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| waxy lipid (mycolic acid) bound to peptidoglycan |
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| 2 examples of acid fast cell wall bacteria |
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| 1. Mycobacterium - causes TB 2. Nocardia |
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| mycoplasma bacteria |
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| -lack cell walls -there are sterols in plasma membrane help protect from lysis -smallest of all bacteria, most contaminating in labs |
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| archea cell wall composition |
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| pseudomurein or pseudoPG lacks NAM and D-amino acids |
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| Plasma membrane composition |
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| phopholipid bilayer and proteins |
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| fluid mosaic model |
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| lipids and proteins are free to move around, about as viscous as olive oil |
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| functions of plasma membrane |
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| -selective permiability -enzymes for ATP production (lack mitochondria) -photosynthetic pigments |
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| damage to plasma membrane caused by |
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| 1. alcohol 2. detergent 3. polymyxin antibiotics casue leakage,death |
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| simple diffusion |
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| passive transport, usually gaseous molecules |
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| facilitated diffusion |
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| passive, larger molecules ex. glycerol goes through transporter protein |
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| osmolerity in cell |
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| 0.85%, ex. saline |
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| classical active transport |
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| -uses ATP or PMF -substance not altered across membrane -uses transporter proteins |
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| group translocation |
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| molecular is chemically altered, this prevents it from leaving cell ex. glucose is phosphorolated |
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| what bacteria does not have flagella? |
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| cocci |
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| flagellin proteins in the filament are |
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| H proteins, recognized by immune system ex. E Coli |
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| monotrichous |
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| 1 flagellum at 1 end |
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| ampthitrichous |
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| 1 flagellum at each end |
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| lophotrichous |
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| many flagellum at one end |
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| peritrichous |
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| entire cell wall has flagella |
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| chemotaxis and phototaxis |
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| movement towards or away from a chemical or light |
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| what bacteria causes stomach ulcers |
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| Helicobacter pylaorii strong flagella can swim through mucous |
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| what bacteria causes stomach ulcers? |
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| Helicobacter pylaorii strong flagella can swim through mucous |
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| mode of movement by bacteria in ocean |
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| gaseous vesicles |
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| what type of cells have pili and fimbriae? |
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| gram negative |
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| function of pili |
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| gliding/twitching movement DNA transfer |
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| Fimbriae |
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| used to attach to things, eg inside of small intestine |
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| structures found in cytoplasm |
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| DNA and ribosomes |
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| bacterial chromosome (nucleoid) characteristics (4) |
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| 1. no nuclear membrane 2. no histones 3. circular DNA 4. Haploid DNA (only 1 copy of each gene) |
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| plasmids description |
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| circular, double stranded DNA, extra-chromosomal autonomis from nucleoid not required by cell |
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| benefits of plasmids |
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| can contain genes for: -antibiotic resistance -toxic metal resistance -production of enzymes |
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| transfer of plasmids |
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| takes place through pili |
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| function of ribosomes |
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| make proteins |
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| somposition of bacterial ribosome |
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| small subunit = 30S large subunit = 50S complete ribosome = 70S |
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| human ribosome complete unit |
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| 80S |
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| antibiotic effect on ribosomes |
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| antibiotics can be targeted towards bacterial ribosomes without harming human ribosomes |
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| content and use of metachromatic granule |
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| phosphate, used to make ATP |
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| presence of metachromatic granule indicates what species of bacterium? |
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| Corynebacterium diphtheriae |
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| who produces endospores? |
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| gram + |
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| when are endospores produced? |
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| when a bacterium is stressed because of lack of C or N |
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| how long can endospores survive? |
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| 100k+ years |
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| the process of endospore formation is known as |
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| sporulation |
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| endospores are made of what? |
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| DPA dipicolnic acid |
