CH. 1 + 2

• microorganism


  can be micro or macroscopic; must have simple structure, lacking distinction
• cellular micros


  fungi, protists, bacteria, and archae
• acellular micros

  viruses, viroids, satellites, prions
• prokaryotes


  lack membrane bound nucleus, other organelles
• eukaryotes


  more complex, large
• domain Bacteria


  single-celled, cell wall with peptidoglycan, and lack a membrane bound nucleus
• domain Archaea


  unique RNA, lack peptidoglycan, unique membrane, unusual metabolism, and live in extreme environments
• domain Eukarya


  protists like slime molds, algae, protozoa, and water molds; fungi like yeast and mold
• viruses


  have protein and nucleic acids, require hosts to replicate
• viroids


  have RNA
• prions


  have proteins
• ribozymes


  earliest RNA molecules; form peptide bonds, perform work and replication
• RNA


  carries out gene expression, protein synthesis, and uses ATP as energy
• universal phylogenic tree


  derives values of evolutionary distance between organisms by comparing rRNA
• endosymbiotic hypothesis


  bacterial lineage and origin of mitochondria, chloroplasts, and hydrogenosomes
• cellular microorganisms


  evolution caused by mutation
• leeuwenhoek (1623 - 1723)


  first person to observe and accurately describe microorganisms
• redi


  discredited spontaneous generation with maggots and meat experiment
• pasteur


  discredited spontaneous generation with swan neck flask experiments
• tyndell


  discredited spontaneous generation with proof that dust has micros
• koch's postulates


  micro must be present in every sick person, and absent in healthy people; micro must be isolated and grown in a pure culture, and cause the same disease
• microscopy


  manipulating illumination sources; light is refracted from passing through a medium
• refractive index


  how greatly a substance slows the light
• focal length


  the distance between the lens and the focal point; the short the focal length the more magnification
• resolution


  the ability of the lens to separate or distinguish small objects from each other; shorter wavelength = greater resolution
• RP = wavelength / 2NA
• bright-field microscope


  dark image with a bright background
• dark-field microscope


  bright image with a dark background
• phase contact microscope


  converts differences in refractive indices and cellular density into variations in light intensity; observes living cells
• fluorescence microscope


  UV, violet, or blue light exposure to fluorochrome stained specimens
• confocal microscope


  uses laser beam and computer interface to create 3D composites
• staining


  increases visibility, preserves specimens, and accentuates features; heat/chemical fixation then staining
• differential stains


  gram staining, acid staining, e.g. ; detects presence or absence of structures
• electron microscopy


  uses electron beam instead of light for higher resolution and detail because the wavelengths are shorter
• transmission electron microscope


  thin and thick regions of specimen scatter electrons differently causing denser areas to appear darker; heavy metals are used to fix and stain
• cryotomography


  rapid freezing to preserve specimen for vacuum
• scanning electron microscope


  produces 3D image, in-situ location of micros
• scanning probe microscopy


  100 million x magnification; uses tunneling with steady current of electrons or atomic force with sharp probe
• needham/spatanalli


  broth-boil-seal; growth for first person and no growth for second person respectively
• lister


  surgical instruments