MCB100 Introductory Microbiology January 23, 2019

1. MCB100 Introductory Microbiology January 23, 2019 Flavin Adenine Dinucleotide is an enzyme cofactor that acts as an electron carrier. It is found in almost all living organisms. Image From: wikipedia/commons/3/36/FAD.png

2. The Study of Fermentation In the 1800s, the term fermentation was used to mean the production of alcohol and acids from sugars, the decomposition of wastes or putrefaction of meat or dairy products. Beer, wine and vinegar have been produced for thousands of years, but Pasteur and other early Microbiologists learned that yeast are needed to make alcohol while bacteria usually produce acidic products. Pasteurization - the use of heat to kill undesirable microorganisms in a beverage Buchner did some of the first studies of enzymes. He showed that cell free extracts of yeast could convert sugar to alcohol. (The term “enzyme” is derived from zymos which was Greek for leavening or yeast.) Some Products Made With the Help of Microorganisms: Cheese, Beer, Wine, Spirits, Soy Sauce, Vinegar, Yogurt, Sour Cream, Raised Bread, Amino acids, vitamins, antibiotics, vaccines, hormones, solvents, enzymes, tea, food thickening agents

3. Development of the Science of Microbiology If you put the following historical events in chronological order, which one was earliest? A. Alexander Fleming discovers the antibiotic penicillin. B. Some unknown person discovered how to make wine. C. Robert Koch identifies the specific types of bacteria responsible for anthrax and tuberculosis and cholera. D. Antony Van Leeuwenhoek publishes a description of bacteria. E. Girolamo Fracostoro suggests that invisible creatures may be involved in disease.

4. Development of the Science of Microbiology If you put the following historical events in chronological order, which one was earliest? A. Alexander Fleming discovers the antibiotic penicillin. 1929 B. Some unknown person discovered how to make wine. (Thousands of years ago.) C. Robert Koch identifies the specific types of bacteria responsible for anthrax and tuberculosis and cholera. 1869 - 1890 D. Antony Van Leeuwenhoek publishes a description of bacteria. 1676 E. Girolamo Fracostoro suggests that invisible creatures may be involved in disease. 1546

5. The Chicken or the Egg? Which event occurred first? • Which one of the following statements about the development of the science of Microbiology is TRUE? • The yeast Saccharomyces cerevisiaewas identified before people were able to use it to turn juice into wine. • Viruses were discovered before the invention of thepractice of vaccination to avoid smallpox infection. • The discovery that plants are composed of cells came before the discovery that animals are composed of cells. • D. The discovery that DNA is the genetic material in cells came before the discovery that some microorganisms make enzymes that degrade DNA.

6. The Chicken or the Egg? Which event occurred first? • Which one of the following statements about the development of the science of Microbiology is TRUE? • The yeast Saccharomyces cerevisiaewas identified before people were able to use it to turn juice into wine. • Viruses were discovered before the invention of thepractice of vaccination to avoid smallpox infection. • The discovery that plants are composed of cells came before the discovery that animals are composed of cells. (TRUE The cell wall makes it easier to observe the boundary between plant cells.) • D. The discovery that DNA is the genetic material in cells came before the discovery that some microorganisms make enzymes that degrade DNA.

7. Often, practice proceeds theory. People have used microorganisms to make products or have fought them to prevent spoilage or disease, without a complete understanding of what was going on. Alcohol Fermentation Production of Beer and wine predates the discovery of yeast by thousands of years. Vaccination Against Viral Infection Jenner developed vaccination to give people immunity to smallpox in 1789. (This was an improvement on inoculation.) Pasteur developed rabies vaccine in 1885. (This was a rushed job that was done in a crisis situation to save a boy’s life.) Ivanowski discovered Tobacco Mosaic Virus in 1892. Use of Cleanliness and Disinfectants to Fight Infectious Disease Semmelweis used handwashing to stop the spread of puerperal fever in 1847. Nightingale introduced antiseptic nursing practices in military hospitals in 1855. Lister introduced antiseptic practices in surgery in 1867. Koch showed that anthrax in cattle was caused by Bacillus anthracis in 1876.

8. C. Some important events in the history of microbiology. 1546 Italian physician Girolamo Fracostoro suggests that invisible organisms may be involved in causing disease. This is the first articulation of the germ theory of disease. 1668 Francesco Redi demonstrates fallacies in the theory of spontaneous generation involving flies. 1676 Dutch linen merchant Antony Van Leeuwenhoek observes bacteria and protozoa using a simple microscope of his own construction. 1776 Lazzaro Spallanzani conducted more experiments that seemed to disprove the theory of spontaneous generation. 1796 Edward Jenner introduces a vaccination for smallpox. 1839 Theodor Schwann and Matthias Schleiden formalize the theory that all living things are composed of cells. 1847 Hungarian physician Ignaz Semmelweis institutes hand-washing in a hospital. 1861 Louis Pasteur finally kills off the idea of spontaneous generation by showing that bacteria do not just appear in sterilized media. 1867 Joseph Lister publishes the first work on antiseptic surgery. 1876 Robert Koch shows that anthrax is caused by a specific microorganism which he calls Bacillus anthracis. 1881 Pasteur develops a vaccine that protects animals from anthrax. Koch introduces pure culture techniques for handling bacteria in the laboratory. 1884 Koch’s postulates are formally outlined. 1890 Behring and Kitasato discover antibodies in serum from immunized animals that neutralize toxins of diphtheria and tetanus. 1892 Ivanovski discovers Tobacco Mosaic Virus an infectious agent that is transmitted in a cell-free filtrate. 1897 Eduard Buchner discovers enzymes, proteins that cause biochemical reactions to proceed at a much faster rate than they would if there was no catalyst present. 1898 Ross and Grassi demonstrate that malaria is transmitted by mosquitoes. 1899 Beijerinck shows that Tobacco Mosaic Virus reproduces in living cells. 1910 Francis Rous discovers viruses that can cause cancer. 1928 Frederick Griffith discovers genetic transformation in Streptococcus pneumonia. 1929 Alexander Fleming discovers penicillin. 1944 Avery, MacLeod and McCarty show that DNA is the genetic material. 1973 Berg, Boyer and Cohen develop techniques to produce recombinant DNA in vitro. 1977 Carl Woese used molecular analysis to discover the difference between Bacteria and Archaea

9. Four Eras in the History of Microbiology 1) Traditional Practices – Ancient Times Making products using microorganisms without any knowledge of the existence of microorganisms. Examples: beer, wine and cheese production 2) The “Golden Age” of Microbiology – Late 1800s Pasteur, Buchner, Koch, Lister, Erlich and others discover the role of microorganisms in fermentation and infectious diseases and develop techniques to control microorganisms. 3) The “Classical Age” of Microbiology – Early 1900s Fleming, Florey, Waksman, Salk, Weizmann and others develop methods to produce antibiotics, enzymes, vaccines and organic solvents using natural strains of microorganisms. 4) The Biotechnology Era – Late 1900s to Present Recombinant DNA technology is used to create new strains of microorganisms that can produce desirable products.

10. MCB100 Introductory Microbiology 2019 The Chemistry of Microorganisms (Chapter 2 of Microbiology by Bauman)

11. Some Important Chemistry Terms Mixture: a substance (or sample) that can be broken down into different parts by physical manipulations that don’t necessarily involve chemical changes Compound: a pure substance that can be broken down into different parts only by chemical reactions Element: a pure substance that can’t be broken down into different parts by chemical reactions Molecule: the smallest particle possible for a compound Atom: the smallest particle possible for an element

12. What is an Organic Compound? An Organic Compound, to a chemist, is a chemical substance that is composed of at least 2 carbon atoms that are covalently bonded and at least 1 hydrogen atom. Organic = from an organismMethane, CH4, isn’t considered to be organic because it has only 1 carbon atom and can be made by volcanoes, which are definitely not living creatures. But, methane can be made by living creatures, and organic chemists often use methane derivatives as examples when teaching concepts in organic chemistry. Urea (NH2-CO-NH2) is considered to be organic because it is found in urine, which comes from animals. Also, in 1828, Friedrich Wohler showed that urea could be synthesized from inorganic substances. This was an important historical event in the development of chemistry as a science.

13. Elements That Are Common In Living Matter Choose the statement that is TRUE. A. Ca is the symbol for carbon. B. Sodium and Chlorine atoms form chemical associations with other elements primarily through covalent bonds. C. An oxygen atom can normally form 4 covalent bonds. D. The chemical symbol for sodium is S. E. Nitrogen atoms, when paired with hydrogen, carbon or other nitrogen atoms, normally form 3 covalent bonds.

14. Elements That Are Common In Living Matter Choose the statement that is TRUE. A. Ca is the symbol for carbon. False - Ca is Calcium, C is Carbon B. Sodium and Chlorine atoms form chemical associations with other elements primarily through covalent bonds.False – NaCl is an ionic compound C. An oxygen atom can normally form 4 covalent bonds. F2 bonds D. The chemical symbol for sodium is S. FSodium is Na, S is Sulfur E. Nitrogen atoms, when paired with hydrogen, carbon or other nitrogen atoms, normally form 3 covalent bonds.True - NH3 H3C-NH2 N=N

16. REDOX REACTIONS An Oxidation-Reduction reaction involves a transfer of electrons from one atom (or group of atoms) to another atom (or group).An oxidation is a loss of electrons. A reduction is a gain of electrons. Because: electrons have a negative charge.   2Na + Cl2 2NaCl (Na+, Cl-)The sodium atoms go from a redox state of 0 to +1 when they lose an electron, while the chlorine atoms go from a redox state of 0 (in Cl2) to -1 when they gain an electron. The sodium is the reducing reagent because it supplies the electron that reduces the charge of the chlorine atom. The chlorine is the oxidizing reagent because it accepts (or takes) the electron from the sodium atom, thus causing the sodium to become a positively charged ion.

18. Inorganic Compounds and Ions That You Should KnowWater H2OSodium Chloride NaCl (aka: table salt) Na+ Cl-   Sodium Hydroxide NaOH (aka: lye) Na+ OH- Hydrochloric acid HCl H+ Cl-   Ammonia NH3   Ammonium Hydroxide NH4OH NH4+ OH- Potassium Nitrate KNO3 (aka: saltpetre) K+ NO3- Sodium Nitrite NaNO2 Na+ NO2- Hydrogen Sulfide H2S (aka: rotten egg gas) Sulfuric Acid H2SO4 2 H+ SO4-2 (sulfate)   Sodium Sulfate Na2SO4 2Na+ SO4-2 Iron Fe Ferrous Chloride FeCl2 (aka: Iron II Chloride) Fe2+ 2 Cl- Ferric Chloride FeCl3 (aka: Iron III Chloride) Fe3+ 3Cl-

19. Which one of the following compounds contains the most oxygen atoms per molecule? A. Ammonia B. Ammonium hydroxide C. Potassium nitrate D. Hydrogen sulfide E. Water

20. Which one of the following compounds contains the most oxygen atoms per molecule? A. Ammonia NH3 B. Ammonium hydroxide NH4OH C. Potassium nitrate KNO3 D. Hydrogen sulfide H2S E. Water H2O