Microbiology: A Systems Approach - Chemistry of Biology

Because learning changes everything. ® Chapter 02 The Chemistry of Biology Microbiology A Systems Approach Seventh Edition Marjorie Kelly Cowan, Heidi Smith © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of Mc...

Because learning changes everything. ® Chapter 02 The Chemistry of Biology Microbiology A Systems Approach Seventh Edition Marjorie Kelly Cowan, Heidi Smith © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  Section 2.1: Atoms, Bonds, and Molecules: Fundamental Building Blocks Learning Outcomes Explain the relationship between atoms and elements. List and define four types of chemical bonds. Differentiate between a solute and a solvent. Provide a brief definition of pH. © McGraw Hill, LLC 2  Atoms, Bonds, and Molecules Matter: all tangible materials that occupy space and have mass Atom: a tiny particle that cannot be subdivided into smaller substances without losing its properties Properties of atoms: Protons (p ) : positively charged, found in the nucleus Neutrons (n0 ) : no charge, also found in the nucleus Electrons (e- ) : negatively charged, surround the nucleus © McGraw Hill, LLC 3  Models of Atomic Structure Access the text alternative for these images © McGraw Hill, LLC 4  Major Elements of Life and Their Primary Characteristics 1 Element: An atom with a characteristic atomic structure and predictable chemical behavior Isotopes: Variant forms of the same element that differ in the number of neutrons Radioactive isotopes: Have unstable nuclei that spontaneously release energy in the form of radiation Used in research and medical applications © McGraw Hill, LLC 5  Major Elements of Life and Their Primary Characteristics 2 Element Atomic Atomic Examples of Significance in Microbiology Symbol Mass Ionized Forms Calcium Ca 40.1 Part of outer covering of certain shelled Ca2  amoebas; stored within bacterial spores Carbon C 12.0 Principal structural component of CO32  biological molecules Carbon C-14 14.0 Radioactive isotope used in dating fossils Chlorine Cl 35.5 CO32  Component of disinfectants, used in water purification Cobalt Co 58.9 Cl Trace element needed by some bacteria to synthesize vitamins Cobalt Co-60 60 Co2  , Co3  An emitter of gamma rays; used in food sterilization; used to treat cancer Copper Cu 63.5 Necessary to the function of some Co2  , Co3  enzymes; Cu salts are used to treat fungal and worm infections Cu , Cu2  © McGraw Hill, LLC 6  Major Elements of Life and Their Primary Characteristics 3 Element Atomic Atomic Examples of Significance in Microbiology Symbol Mass Ionized Forms Hydrogen H 1 Necessary component of water and many organic H molecules; H2 gas released by bacterial metabolism Hydrogen H3 3 Has two neutrons; radioactive; used in clinical H  laboratory procedures Iodine I 126.9 A component of antiseptics and disinfectants; I  used in the Gram stain Iodine I-131, I-125 131, 125 Radioactive isotopes for diagnosis and treatment of cancers I Iron Fe 55.8 Necessary component of respiratory enzymes; required by some microbes to produce toxin Fe2 , Fe3 Magnesium Mg 24.3 A trace element needed for some enzymes; component of chlorophyll pigment Manganese Mn 54.9 Mg2 Trace element for certain respiratory enzymes Nitrogen N 14.0 Mn2 , Mn3 Component of all proteins and nucleic acids; the major atmospheric gas NO3 © McGraw Hill, LLC 7  Major Elements of Life and Their Primary Characteristics 4 Element Atomic Atomic Examples of Significance in Microbiology Symbol Mass Ionized Forms Oxygen O 16.0 An essential component of many organic molecules; molecule used in metabolism by many organisms Phosphorus P 31 A component of ATP, nucleic acids, cell PO 3 4 membranes; stored in granules in cells Phosphorus P-32 32 Radioactive isotope used as a diagnostic and therapeutic agent PO34 Potassium K 39.1 Required for normal ribosome function and protein synthesis; essential for cell membrane K permeability Sodium Na 23.0 Necessary for transport; maintains osmotic Na pressure; used in food preservation Sulfur S 32.1 Important component of proteins; makes disulfide bonds; storage element in many bacteria SO24 Zinc Zn 65.4 An enzyme cofactor; required for protein synthesis and cell division; important in regulating DNA Zn2 © McGraw Hill, LLC 8  Electron Orbitals and Shells Orbitals: Pathways in which electrons rotate around the nucleus Represent volumes of space in which an electron is likely to be found Access the text alternative for these images © McGraw Hill, LLC 9  The Periodic Table Access the text alternative for these images © McGraw Hill, LLC 10  Bonds and Molecules 1 Molecule: A chemical substance that results from the combination of two or more atoms O2, N2 Compound: A molecule composed of two or more different elements H2O, C6H12O6 © McGraw Hill, LLC 11  Bonds and Molecules 2 Chemical bonds: Result when two or more atoms share, donate (lose), or accept (gain) electrons Valence: The number of electrons in the outermost shell of an element Determines the degree of reactivity and the type of bonds an element can make © McGraw Hill, LLC 12  Three Types of Bonding Access the text alternative for these images © McGraw Hill, LLC 13  Covalent Bonds and Polarity 1 Covalent bonds: Form between atoms that share electrons rather than donating or receiving them Single covalent bonds share a pair of electrons (H2) Double covalent bonds share two pairs of electrons and are more rigid than single bonds (O2) Access the text alternative for these images © McGraw Hill, LLC 14  Covalent Bonds and Polarity 2 Polar molecule: Results when a molecule is formed between two atoms that have different electronegativity or ability to attract electrons Nonpolar molecule: Molecules formed when atoms have similar electronegativity Access the text alternative for these images © McGraw Hill, LLC 15