MICRO-s10_03corr - BIOL 240 General Microbiology General...

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Unformatted text preview: BIOL 240: General Microbiology General Spring 2010 Rm. 22-116 R, Jan. 28, 2010 Dr. Nathan Staples (Ph.D., UCSB 2002) http://www.smccd.edu/accounts/staplesn/biol240/ 1. Pre-Lab W riteups: Be sure to prepare before each Lab Writeups Be Monday’s Monday’s labs (for BOTH Mon. & Wed.)!! – (What? Why? How? are we doing in the lab??) 2. Pre-lecture slides and study guides available on lecture course website by the night before. • (Print WISELY!! If you choose to do so..) 3. Bi-weekly lab quizzes – practice quiz by this weekly practice Th./Fri.. Th./Fri.. (Not active yet!!!) – http://smccd.mrooms.net/ -- login with G# and Password login ( = birth date, MMDDYY, if new) birth REVIEW 1. Diagram and describe how Louis Pasteur proved how life truly arises. Diagram Louis 2. Describe the work and significance of the discoveries of van Describe Leeuwenhoek, Pasteur, Jenner, Koch and Fleming….. and 3. Diagram & describe Robert Koch’s postulates, and explain their Diagram Robert and significance significance to modern medicine and infectious disease……. TODAY’s Objectives: Students should be able to….. 1. Describe the threat of 4 emerging infectious diseases, and the type of Describe emerging and organism organism that causes each. 2. Ch. 2: Describe the 6 “Elements of Life”, their relative electron affinities Describe “Elements their electron and bonding properties, and their roles in biomolecules. 3. Describe how the Octet Rule affects chemical bonding, and distinguish Describe Octet affects between the relative strengths of the 3 main chemical bonds formed in main f ormed biomolecules. biomolecules. 4. Distinguish between 4 types of chemical interactions and reactions Distinguish types common in living systems. 5. List 5 special properties of water that make it the “perfect” medium for life. List properties 1 1.4) 1.4) Modern Developments in in Microbiology • Bacteriology is the study of bacteria. • Mycology is the study of fungi. • Parasitology is the study of protozoa and is parasitic parasitic worms. • Recent advances in genomics, the study of Recent genomics the an organism’s genes, have provided new tools tools for classifying microorganisms. Modern Developments: Immunology & Virology • Immunology is the study of is acquired acquired resistance to disease. to – Vaccines and interferons are being Vaccines investigated to prevent and cure viral diseases. diseases. • 1933: Rebecca Lancefield 1933: Rebecca proposed proposed the use of immunology to identify some bacteria according to serotypes – (variants within a species = “strains” or (variants “subspecies”). “subspecies”). Figure 1.4 • Virology is the study of viruses. 2 Modern Modern Developments: Recombinant Recombinant DNA Technology • Microbial genetics: The study of how microbes The inherit inherit traits • Molecular biology: The study of how DNA directs The protein protein synthesis • Genomics: The study of an organism’s genes; has The provided provided new tools for classifying microorganisms • Recombinant DNA: DNA made from two DNA different sources. – 1960s, Paul Berg inserted animal DNA (SV40) into bacterial into DNA DNA and the bacteria produced an animal protein. – Recombinant DNA Technology / Genetic Engineering involves microbial Recombinant genetics genetics and molecular biology. Made Genomics possible!! Modern Developments: Major Discoveries Using microbes (Many Nobel prizes!): – George Beadle and Edward Tatum showed George Beadle and Tatum showed that genes encode a cell’s enzymes (1942) genes – Oswald Avery, Colin MacLeod, and Maclyn Oswald Avery Colin MacLeod and McCarty showed McCarty showed that DNA was the hereditary hereditary material (1944). – Francois Jacob and Jacques Monod Francois Jacob and Monod discovered discovered the role of mRNA in protein synthesis synthesis (1961). • & One gene – one polypeptide (protein) theory One 3 1.5) 1.5) Microbes and Human Human Welfare Microbial Ecology – Bacteria recycle carbon, nitrogen, Bacteria nutrients, sulfur, and phosphorus that can be be used by plants and animals. A. Bioremediation • Bacteria degrade organic Bacteria matter matter in sewage. • Bacteria degrade or Bacteria detoxify pollutants such as as oil and mercury. 4 B. B. Biological Insecticides Insecticides • Microbes that are pathogenic to insects Microbes – alternatives to chemical pesticides alternatives – prevent insect damage to agricultural prevent crops crops and disease transmission Bt TX- • Bacillus thuringiensis infections infections are fatal in many insects but harmless to other animals including including humans and to plants. Bt TX+ C. C. Modern Biotechnology and Genetic Genetic Engineering • Biotechnology, the use of microbes the to produce foods and chemicals, is centuries centuries old. • Genetic Engineering is a new is technique for biotechnology. – bacteria and fungi can produce a variety of bacteria proteins proteins including vaccines and enzymes. – Missing or defective genes in human cells can Missing be replaced in gene therapy. gene 5 D. Microbes &Human Disease • Bacteria were once classified as plants which Bacteria gave rise to use of the term flora for flora for microbes. microbes. • This term has been replaced by Microbiota. This Microbiota – Microbes normally present in and on the human Microbes body are called normal microbiota. normal Normal & Pathogenic Microbiota Pathogenic 1. Normal microbiota: pathogens. pathogens. • Normal microbiota produce growth factors such as Normal folic folic acid and vitamin K. prevent prevent growth of 2. Resistance: off disease. is is the ability of the body to ward • Resistance factors include skin, stomach acid, and Resistance antimicrobial antimicrobial chemicals. 3. Pathogenesis: W hen When an infectious microbe overcomes overcomes the host’s resistance, disease results. – Emerging Infectious Diseases (EID): New diseases New and and diseases increasing in incidence……. 6 E. Emerging Infectious Diseases 1. Bovine Spongiform Bovine Encephalopathy Encephalopathy – Prion. – – Also causes Creutzfeldt-Jakob Jakob disease disease (CJD). New-variant CJD in humans variant CJD in related to cattle fed sheep offal (entrails) (entrails) for protein. 2. Escherichia coli O157:H7 – – – Toxin-producing strain of E. coli. producing E. Fist seen in 1982. Leading cause of diarrhea worldwide. Emerging Infectious Diseases 3. Acquired ImmunoDeficiency Syndrome (AIDS) – Human immunodeficiency virus (HIV) – First identified in 1981. – Worldwide epidemic infecting 40 million people; Worldwide • 14,000 new infections every day. – Sexually transmitted disease affecting Sexually males males and females. 4. Anthrax – – – – Bacillus anthracis In In 1877, Koch proved B. anthracis causes anthrax. B. Veterinarians and agricultural workers are at risk of cutaneous anthrax. In In 2001, dissemination of B. anthracis via mail infected 22 people. B. 7 Chapter 2 Chemical Principles 2.1) Chemistry • Chemistry is the study of interactions is between between atoms and molecules. • The atom is the smallest unit of matter The atom is that that enters into chemical reactions. • Atoms interact to form molecules. Atoms molecules 8 A. The Study of Atoms Atoms are composed of • Electrons: negatively charged particles • Protons: positively charged particles • Neutrons: uncharged particles The Study of Atoms • Protons and neutrons are in the nucleus. Protons nucleus • Electrons move around the nucleus. Figure 2.1 9 B. Chemical Elements • Each chemical element has a different number Each of of protons. • Isotopes of an element are atoms with of different numbers of neutrons. – Isotopes of oxygen are: 16 8 17 8 18 8 O O O Mass # = protons + neutrons Atomic # = protons (identifies element!) CHNOPS!! * 6 make up make 98% of all living living mass Table 2.1 10 C. Electronic Configurations • Electrons are arranged in electron shells Electrons electron corresponding corresponding to different energy levels. energy • Octet Rule: past H and He, all other all atoms are most stable with an outer electron shell filled with 8 Electrons!! Electrons – Closer to 8 = tend to grab electrons! – Further from 8 = tend to give-up electrons! Electronic Configurations Table 2.2.1 11 Electronic Configurations Table 2.2.2 D. D. How Atoms Form Molecules: Molecules: Chemical Bonds • Atoms combine to complete the Atoms outermost outermost shell. • The number of missing or extra The electrons in this shell is the valence. valence – Determines the number and types of Determines bonds bonds that can be formed. 12 How How Atoms Form Molecules: Chemical Chemical Bonds • A compound is a molecule that contains compound is different different kinds of atoms. H2O • The forces holding atoms in a compound The are are chemical bonds. How How Atoms Form Molecules: Chemical Chemical Bonds • The number of protons and electrons is The equal equal in an atom. • Ions are atoms that have gained or lost are electrons electrons and are charged. Figure 2.2a 13 1. Ionic Bonds • Ionic bonds are attractions between ions of are opposite charge. – One atom loses electrons and another gains One electrons. electrons. Figure 2.2b 2. Covalent Bonds • Covalent bonds form when two atoms bonds share share one or more pairs of electrons. Figure 2.3a 14 3. Hydrogen Bonds • Hydrogen bonds form when a hydrogen Hydrogen atom covalently bonded to an O or N atom in in another molecule. Figure 2.4 E. Chemical Reactions • Chemical reactions involve the making Chemical or or breaking of bonds between atoms. • A change in chemical energy occurs change during during a chemical reaction. – Endergonic reactions absorb energy. – Exergonic reactions release energy. 15 1. Synthesis Reactions • Occur when atoms, ions, or molecules combine to Occur form form new, larger molecules A Atom, ion, or molecule A + B Atom, ion, or molecule B AB New molecule AB • Anabolism is the synthesis of molecules in a cell. 2. Decomposition Reactions • Occur when a molecule is split into smaller Occur molecules, molecules, ions, or atoms. AB New molecule AB Breaks down into A Atom, ion, or molecule A + B Atom, ion, or molecule B • Catabolism is the decomposition reactions in a cell. 3. Exchange Reactions • Are part synthesis and part decomposition. NaOH + HCl NaCl + H2O [ 4.) Reversible Reactions ] • Can readily go in either direction. – Common in LIVING SYSTEMS!!!!.... • Each direction may need special conditions. A + B AB Heat Water 16 ...
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