Micro Exam 1 Study Guide PDF

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Microbiology Exam 1 Study Guide Chapter 1: Microbiology: An Introduction Prokaryotes: “before a nucleus,” unicellular, lack organelles, no nuclear membrane Eukaryotes: “true nucleus,” uni/multicellular, contain organelles, well-defined nucleus The Three Domain System 1. Domain Bacteria (prokaryotes) - Kingdom Eubacteria - Disease-causing/pathogenic - Virulence: the ability to cause disease - Peptidoglycan (murein): polymer consisting of sugars and amino acids that forms a mesh-like outer layer of the plasma membrane, becoming the cell wall of most bacteria - Reproduction: binary fission (30 minute doubling time) - Energy: organic/inorganic chemicals or photosynthesis 2. Domain Archaea (prokaryotes) - Kingdom Archaebacteria - Not disease-causing/pathogenic, cannot cause food spoilage or live in our bodies - No Peptidoglycan - Pseudopeptidoglycan (pseudomurein): major cell wall component in some archaea, differs from peptidoglycan chemically but similar in structure and function - Reproduction: asexually by binary/multiple fission, fragmentation, or budding - Energy: inorganic chemicals or via the sun (not photosynthesis) - Usually live in extreme environments - Methanogens:methane-producing - Halophiles: grow in/tolerate saline conditions - Thermophiles: grow best in high temperatures 3. Domain Eukarya (Eukaryotes) a. Fungi: - Energy: organic chemicals - Chitin: fibrous substance made of polysaccharides found in the cell walls of fungi - Molds and Mushrooms: multicellular, consist of masses of mycelia (vegetative part of a fungus/fungus-like bacterial colony) consisting of a mass of branching, threadlike, filamentous hyphae - Yeasts: unicellular, microscopic fungus consisting of single oval cells that reproduce by budding, and are capable of converting sugar into alcohol and carbon dioxide. - Mucor: microbial genus of approximately 40 species of molds found In soil, digestive systems, plant surfaces, cheeses, rotten vegetables, iron oxide residue (common bread mold) b. Protista: -Any eukaryote that is not an animal, plant, or fungi i. Protozoa: - Energy: absorb/ingest organic chemicals, autotrophic/heterotrophic - Motility: pseudopods, cilia, flagella - Free-living, parasitic, mutualistic - Cryptosporidiosis: microorganism the lives on dead matter of the GI tract, fecal-oral transmission or from animal to person or person to person via ingesting contaminated food and water ii. Algae: - Energy: photosynthesis - Cellulose: most common organic compound on earth, obtained from wood pulp and cotton,

used to produce cotton, linen, rayon, and for nitrocellulose for explosives, and cellulose acetate for films. c. Plantae: d. Animalia: Viruses

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Acellular (no cells) Consist of a DNA or RNA core surrounded by a protein coat The coat may then be enclosed in a lipid envelope Can only replicate when in a living host cell! Intracellular obligate parasites: rely on the metabolic activity of the host The Origin of Life

1. Spontaneous Generation: the hypothesis that living organisms arise from non-non-living matter - Aristotle: a “vital force” forms life - J. Needham: boiled nutrient broths before pouring into flasks, covered them and discovered teeming organisms later. 2. Biogenesis: the hypothesis that living organisms arise from preexisting life - F. Redi: filled 3 jars with decaying meat: 1. sealed: no maggots, 2. unsealed: maggots; 3. covered with fine mesh: no maggots - L. Spallanzani: boiled nutrient solutions after pouring them into seal flasks and found NO microbial growth - L. Pasteur: used S-shaped flasks to keep microbes out but let air in, flasks showed no sign of life after heating/incubation, neck trapped microbes - microbes and disease relationship, immunity, antimicrobial drugs, demonstrated that microorganisms are present in air and responsible for fermentation, food/beverage spoilage - Pasteurization: the application of a high heat for a short time to kill harmful bacteria in beverages Defense Against Disease 1. Edward Jenner: father of immunology - Inoculated a person with cowpox virus, who was then protected from smallpox - Vaccination: derived from vacca (cow) - Immunity: the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells. 2. Chemotherapy: treatment with chemicals - Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics - Antibiotics: chemicals produced by bacteria and fungi that inhibit or kill other microbes - P. Ehrlich: speculated about “magic bullet” that could destroy a pathogen without harming host -1910: developed Salvarsan: a synthetic arsenic drug to treat Syphilis Koch’s Postulates 1. Association: the suspected causative agent must be found in every case of the disease and be absent from healthy individuals 2. Cultivation/Isolation: the agent must be isolated and grown outside the host 3. Reproduction: when the agent is introduced into a healthy, susceptible host, the host should contract the same disease 4. Re-Isolation: the same agent must be re-isolated from the diseased experimental host

Infectious Diseases

- When a pathogen overcomes the host’s resistance, disease results - Emerging Infectious Diseases (EIDs): new diseases and diseases increasing in incidence - Avian Influenza A, MRSA, West Nile, E. Coli, Ebola, AIDS, ZIKA, Bovine Spongiform Encephalopathy

Chapter 2: The Chemistry of Microbiology Chemical Bonds - Electronegativity: attraction of an atom for electrons 1. Covalent Bonds: sharing a pair of electrons between 2 more more atoms (intramolecular) a. Nonpolar Covalent Bonds: shared electrons spend equal amounts of time around each nucleus - Atoms with similar electronegativities - NO poles exist - Allow of Hydrogen bonding - Ex) Methane, Carbon Dioxide, most hydrocarbons b. Polar Covalent Bond: unequal sharing of electrons - Atoms with significantly different electronegativities - Allows for hydrogen bonding - One partial (+) side and one partial (-) side - Ex) Ammonia, Water 2. Ionic Bonds: when two atoms with vastly different electronegative come together (intramolecular) - Cations (+) and Anions (-) come together - NO sharing of electrons - Ex) Sodium Chloride, most crystalline salts 3. Hydrogen Bonds: weak forces that combine with polar covalent bonds (intermolecular) - Electrical attraction between partially charged H+ and full or partial negative charge on some or different molecule - Weaker than covalent bonds but essential for life - Help stabilize 3-D shapes of large molecules - Ex) DNA Water

- Hydrogen Bonds/2 Polar Covalent Bonds: give water unique properties that make it special and essential for life 1. Solvency: many substances can dissolve in it (bonds make it heavily attracted to other molecules) 2. Surface Tension: due to the cohesion between the molecules (bonds hard to break) 3. Temperature Stabilization: remains liquid across a wide range of temperatures (bonds hard to break)

Acids and Bases -Dissociated by water into component cations and anions 1. Acid: dislocates into H+ and more or more anions (proton donor) - Strong Acids: completely give away H+ - Ex) Battery acid, hydrochloric acid, sulfuric acid 2. Base: alkalis, bonds with H+ when dissolved into water: some dissociate into cabins and OH- (proton acceptor) - Strong Bases: completely gives away OH- in - Ex) Cleaners, milk of magnesium, Sodium oxide 3. The pH Scale: a measure of acidity or alkalinity of water soluble substances (pH!stands for “potential of Hydrogen”). A pH!value is a number from 1 to 14, with 7 as the middle (neutral) point. Values below 7 indicate acidity which increases as the number decreases, 1 being the most acidic. Organic Macromolecules

- Contain Carbon and Hydrogen atoms - Functional groups of common arrangements - Large molecules used by all organisms 1. Lipids: composed of fatty acids: long carbon chains with a carboxyl group (COOH) at 1 end, and glycerol - Hydrophobic a. Fats: triglycerides, molecules made from the combination of one molecule of glycerol with 3 fatty acids! b. Phospholipids: a lipid containing a phosphate group (PO43-) c. Waxes: contain one long-chain fatty acid covalently linked to long-chain alcohol by ester bond - Completely insoluble in water - Lack hydrophilic head d. Steroids: structure composed of four fused rings (3 cyclohexane and 1 cyclopentane) - Ex) Testosterone 2. Carbohydrates: composed of Hydrogen and Oxygen (CH2O)n a. Monosaccharides: glucose, fructose, galactose, ribose b. Disaccharides: sucrose, lactose, maltose b. Polysaccharides: cellulose and glycogen - Functions: - Storage of chemical energy/ready source - Part of the backbones of nucleic acids - Converted to amino acids - Form cell walls - Involved in intracellular intracellular reactions between animal cells 3. Proteins: mostly composed of Carbon, Hydrogen, and Oxygen, Nitrogen, Sulfur - Functions: - Structure - Enzymatic Catalysis - Regulation/Transportation - Defense/Offense - Amino Acids: the monomers that make up proteins - Most organisms use 21 in the synthesis of proteins - Side groups affect how amino acids interact ad how a protein interacts with other molecules - A covalent (peptide bond) is formed between amino acids by dehydration synthesis reaction)

4. Nucleic Acids: DNA/RNA/genetic material in organisms - RNA also acts as enzyme, binds amino acids, and helps form polypeptides - Nucleotides/Nucleosides: monomers that make up nucleic acids - 3 parts of a nucleotide: phosphate group, pentose sugar (deoxyribose/ribose), a nitrogenous base (ATGCU) - Structure: - 3 H bonds form between C and G - 2 H bonds form between T and A (DNA) or U and A (RNA) - DNA: double stranded in most cells/viruses, 2 strands complementary/antiparallel - Functions: - DNA is genetic material in all organisms and many viruses - Carries instructions for synthesis of RNA and proteins - Controls synthesis of all molecules in an organism - ATP: short-term, recyclable energy for all cells, P-P bonds of ATP are high-energy bonds...