1 Notes for Exam 1 Review Lecture 1 Origins of Life 1 Bacteria are found everywhere on every surface but too small to be visible to the naked eye a Found in extreme environments salt halophile pressure barophile temperature thermophile hyperthermophile or psychrophile pH acidophile neutrophile or alkaliphile 2 More bacteria than any other lifeform play a huge role in history and biology recycle crucial elements S O N P C to usable forms 3 3 7 BYA graphite present meaning that concentrated carbon could mean life findings debated 4 2 7 BYA stromatolites layered rocks with biological origins maybe microfossils 5 Origin of life mechanism not known a Abiogenesis origin from the earth testable b Non earthly origins from space debris testable c Divine creation life created by divine being non testable d Extra terrestrial life came from aliens non testable 6 Pre life Earth conditions water with soluble metals inorganic and organic molecules volcanoes meteorites atmosphere of CO2 H2S SO2 H2 and low O2 7 Multiple experiments done to test abiogenesis hypothesis a Miller Urey used current data to make a model of pre life early atmosphere of water methane ammonia hydrogen added electricity made amino acids Joan Or made adenine from cyanide and ammonia b Butlerow carbohydrates like ribose form from formaldehyde formose reaction c d Orgel RNA Chains made abiotically e Eigen and Spiegelman RNA catalysis and replication 8 Lipids made of light and polycyclic aromatic hydrocarbons can be made from primordial mixes a Can self assemble sometimes as bilayers and some have self replicating catalytic properties b Some split after reaching certain sizes c Vesicles created could concentrate molecules d Could have formed primitive nanocells the precursor to cells as we know them 9 Early earth s atmosphere of low O2 necessitated fermentative metabolism and anaerobic respiration a FM extracts energy from organic molecules but leaves some energy In the molecules produces alcohols aldehydes ketones acids methane CO2 ammonia hydrogen b AAR donates electrons to receptors that are not oxygen such as metals Fe Mn Co S U inorganic molecules nitrate to nitrite sulfate to sulfide CO2 to acetate or organic Molecules fumerate to succinate c Anoxic Photosynthetic Bacteria Purple S Purple Non S Green S Green Non S Heliobacteria generate ATP From light excess energy can be used to fix CO2 N 2 d Lithotropy uses inorganic substrates such as phosphate H sulfide ammonia nitrite Fe as electron donors to drive energy acquisition using either organic carbon or carbon dioxide as a source of carbon for constructing cellular materials 10 Oxygenic photosynthesis developed in cyanobacteria about 2 5 BYA very efficient process to generate ATP by taking electrons from water and adding them to CO2 to make organic carbon and oxygen Less CO2 means less heat trapped in atmosphere snowball earth a b Oxygen pollutes the atmosphere free metals oxidized c Most organisms can t handle oxygen mass extinction and evolution pushes forward again make catalase to neutralize peroxides and oxygen becomes the substrate of respiration 11 Life on Mars less atmosphere so more radiation from sun smaller so less gravity no magnetosphere atmosphere made of CO2 Ar N O CO no current evidence of past or current life but now evidence of liquid water Lecture 2 Microscopy 1 Units of measurement metric system based on 10 used in science bacteria usually around 1 um 10 6 m viruses around 75 nm 2 Antoni van Leeuwenhoek considered the father of microbiology using the microscopes he 3 himself constructed he was the first to observe microorganisms or animalcules Light microscopy Light passes from source through condenser lens diaphragm controls amount of light into the condenser condenser concentrates light onto specimen light passes through specimen onto objective lens then to the ocular lens 4 Magnification is a function of the lenses and calculated by multiplying the power of the lenses used Ocular LP x Objective LP Total Magnification 5 Resolution Resolving Power ability to distinguish between two objects that are close together 6 Resolution distance 0 612 x numerical aperture Limit of Resolution smallest distance between two points that are able to be seen as distinct 7 8 Electron microscope use electrons to see specimen as opposed to light electrons are shot through a specimen captured by an objective and projector lens and then shown as a fluorescent image scanning transmission 9 Golden Age of Microbiology Koch Pasteur Winogradsky Modern Age discovery of antibiotics discovery that DNA is genetic material DNA structure sequencing PCR 10 Spontaneous Generation Abiogenesis or life arises from non life postulated by Aristotle in 11 Fermentation of wine into vinegar led to pasteurization swan neck flask experiment and 300 BC disproved by scientific method began industrial microbiology 12 Germ Theory by Robert Koch Koch s Postulates Single microorganism causes single disease starts concept of pathogen etiology cause of disease 3 a Causes of disease before Koch witches old age individual or collective sin interference with the natural balance of vital forces humorism b Treatments of disease before Koch prayer banishment bleeding plant extracts 13 Koch s Postulates to prove that a disease is caused by a particular microbe agent a The agent must be present in every case of disease and absent in all healthy cases b The agent must be isolated and cultured in vitro c The disease must be reproduced when a pure culture of the agent is inoculated into a d The agent must be recoverable from the experimentally infected host and shown to be susceptible host identical 14 Sanitation a Semmelweis Vienna 1846 observed that cases of childbed fever were high in clinics by physicians and med students but low when run by midwives because physicians and med students were performing autopsies between deliveries b Had them WASH THEIR HANDS to cut down mortality c Lister Antisepsis disinfection of wounds instruments 15 Chemotherapy Erlich magic bullet must be non toxic to humans 16 Antibiotics Fleming produced by microbes to kill other microbes 17 Lots of ologies pertaining to study of microbes and human health 18 Phenotypic ways to classify microbes a Morphology size shape coccus coccobacillus bacillus spirochete pleomorphic vibrio spirillum filamentous whether they bud have stalks or hypha clustering b Staining properties c Metabolic ability d Habitat e Pathogenicity 19 Genetic way to