Microbiology With Diseases By Body System PDF

PowerPoint® Lecture Presentations prepared by Mindy Miller-Kittrell, North Carolina State University CHAPTER 2...

PowerPoint® Lecture Presentations prepared by Mindy Miller-Kittrell, North Carolina State University CHAPTER 2 The Chemistry of Microbiology © 2018 Pearson Education, Inc.  Atoms Matter—anything that takes up space and has mass Atoms—the smallest chemical units of matter Atomic Structure Electrons—negatively charged subatomic particles circling a nucleus Nucleus—structure containing neutrons and protons Neutrons—uncharged particles Protons—positively charged particles © 2018 Pearson Education, Inc.  Atoms Atomic Structure Element—composed of a single type of atom Atomic number— equal to the number of protons in the nucleus Atomic mass (atomic weight)—sum of masses of protons, neutrons, and electrons © 2018 Pearson Education, Inc.  Atoms Isotopes Atoms of a given element that differ in the number of neutrons in their nuclei © 2018 Pearson Education, Inc.  Atoms Electron Configurations Only the electrons of atoms interact, so they determine atom’s chemical behavior. Electrons occupy electron shells. Valence electrons— electrons in outermost shell that interact with other atoms © 2018 Pearson Education, Inc.  Table 2.1 Common Elements of Life © 2018 Pearson Education, Inc.  Active Exercise How many Protons does Oxygen have? a)16 b)8 c)6 d)4 e)12 g)99 © 2018 Pearson Education, Inc.  Active Exercise How many Protons does Oxygen have? a)16 b)8 c)6 d)4 e)12 g)99 © 2018 Pearson Education, Inc.  Chemical Bonds Chemical bonds—atoms combine by sharing or transferring valence electrons Molecule—two or more atoms held together by chemical bonds Compound—a molecule composed of more than one element © 2018 Pearson Education, Inc.  Chemical Bonds Covalent bond— sharing of a pair of electrons by two atoms Electronegativity— attraction of atom for electrons The more electronegative an atom, the greater the pull its nucleus exerts on electrons. © 2018 Pearson Education, Inc.  Chemical Bonds Nonpolar Covalent Bonds Shared electrons spend equal amounts of time around each nucleus. Atoms with similar electronegativities No poles exist. Carbon atoms form four nonpolar covalent bonds with other atoms. Organic compounds contain carbon and hydrogen atoms. Electronegativity Difference - < 0.4 Polar Covalent Bonds Unequal sharing of electrons due to significantly different electronegativities Most important polar covalent bonds involve hydrogen. Allow for hydrogen bonding Electronegativity Difference – 0.4 – 1.8 © 2018 Pearson Education, Inc.  Think-Pair-Share Assuming the electrical source is completely functional. What may be a reason as to why one of the Lightbulb’s is not lighting up? © 2018 Pearson Education, Inc.  Think-Pair-Share Assuming the electrical source is completely functional. What may be a reason as to why one of the Lightbulb’s is not lighting up? © 2018 Pearson Education, Inc.  Chemical Bonds Ionic Bonds Occur when two atoms with vastly different electronegativities come together Atoms have either positive (cation) or negative (anion) charges. Cations and anions attract each other and form ionic bonds (no electrons shared). Typically form crystalline ionic compounds known as salts Electronegativity Difference - > 1.8 © 2018 Pearson Education, Inc.  Chemical Bonds Hydrogen Bonds Electrical attraction between partially charged H+ and full or partial negative charge on same or different molecule Weaker than covalent bonds but essential for life Help to stabilize 3- D shapes of large molecules © 2018 Pearson Education, Inc.  Table 2.2 Characteristics of Chemical Bonds © 2018 Pearson Education, Inc.  Chemical Reactions The making or breaking of chemical bonds Involve reactants and products Biochemistry involves chemical reactions of living things. © 2018 Pearson Education, Inc.  Chemical Reactions Synthesis Reactions Involve the formation of larger, more complex molecules Require energy (endothermic) Common type is dehydration synthesis Water molecule formed All the synthesis reactions in an organism are called anabolism. © 2018 Pearson Education, Inc.  Chemical Reactions Decomposition Reactions Break bonds within larger molecules to form smaller atoms, ions, and molecules Release energy (exothermic) Common type is hydrolysis Ionic components of water are added to products. All the decomposition reactions in an organism are called catabolism. © 2018 Pearson Education, Inc.  Water, Acids, Bases, and Salts Water Most abundant substance in organisms Many special characteristics due to two polar covalent bonds: Cohesive molecules—generate surface tension Excellent solvent Remains liquid across wide range of temperatures Can absorb significant amounts of heat energy without changing temperature Participates in many chemical reactions © 2018 Pearson Education, Inc.  Water, Acids, Bases, and Salts Salts Compounds that dissociate in water into cations and anions other than H+ and OH– Cations and anions of salts are electrolytes that: Create electrical differences between inside and outside of cell Transfer electrons from one location to another Form important components of many enzymes © 2018 Pearson Education, Inc.  Organic Macromolecules Functional Groups Contain carbon and hydrogen atoms Atoms often appear in arrangements called functional groups. Macromolecules—large molecules used by all organisms: Lipids Carbohydrates Proteins Nucleic acids Monomers—basic building blocks of macromolecules © 2018 Pearson Education, Inc.  Organic Macromolecules Lipids Are all hydrophobic Four groups: Fats (triglycerides) Phospholipids Waxes © 2018 Pearson Education, Inc.  Figure 2.16 Phospholipids. © 2018 Pearson Education, Inc.  Organic Macromolecules Lipids Waxes Contain one long- chain fatty acid covalently linked to long-chain alcohol by an ester bond Lack hydrophilic head Completely insoluble in water © 2018 Pearson Education, Inc.  Organic Macromolecules Carbohydrates Serve as sources of energy. They help form the structural integrity of molecules and serve as recognition sites during intercellular interactions. Types: Monosaccharides Disaccharides Polysaccharides © 2018 Pearson Education, Inc.  Figure 2.18 Monosaccharides (simple sugars). © 2018 Pearson Education, Inc.  Figure 2.19 Disaccharides. © 2018 Pearson Education, Inc.  Figure 2.20 Polysaccharides. © 2018 Pearson Education, Inc.  Organic Macromolecules Proteins Composed mostly of carbon, hydrogen, oxygen, nitrogen, and sulfur Functions: Structure Enzymatic catalysis Regulation Transportation Defense and offense © 2018 Pearson Education, Inc.  Organic Macromolecules Proteins Amino acids The monomers that make up proteins Most organisms use only 21 amino acids in protein synthesis. Side groups affect how amino acids interact with one another and how a protein interacts with other molecules. A covalent peptide bond is formed between amino acids. The building blocks for proteins © 2018 Pearson Education, Inc.  Figure 2.22 Stereoisomers, molecules that are mirror images of one another. © 2018 Pearson Education, Inc.  Figure 2.23 The linkage of amino acids by peptide bonds via a dehydration reaction. © 2018 Pearson Education, Inc.  Levels of Protein structures © 2018 Pearson Education, Inc.  Organic Macromolecules Nucleotides and Nucleic Acids Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the vital genetic material of cells and viruses. RNA also acts as enzyme, binds amino acids, and helps form polypeptides. Nucleic Acids Nucleic acid function DNA is genetic material of all organisms and of many viruses. Carries instructions for synthesis of RNA and proteins Controls synthesis of all molecules in an organism © 2018 Pearson Education, Inc.  Do Genetic’s matter? Take 5 minutes to discuss about Family genetics. Is it important to Nursing? Healthcare? Etc. © 2018 Pearson Education, Inc.  Organic Macromolecules Nucleotides and Nucleic Acids Nucleotides and nucleosides Nucleotides Monomers that make up nucleic acids Composed of three parts: Phosphate Pentose sugar— either deoxyribose or ribose One of five cyclic nitrogenous bases Nucleosides are nucleotides lacking phosphate. © 2018 Pearson Education, Inc.  Organic Macromolecules Nucleic Acids Nucleic acid structure Three H bonds form between C and G. Two H bonds form between T and A (DNA) or U and A (RNA). DNA is double stranded in most cells and viruses. The two strands are complementary. The two strands are antiparallel. © 2018 Pearson Education, Inc.  Table 2.5 Comparison of Nucleic Acids © 2018 Pearson Education, Inc.  Figure 2.27 ATP. © 2018 Pearson Education, Inc.  Conclusion This lecture was an outline of Chapter 2. Please do not hesitate to ask any questions. I am happy to help. You may all get started on In-class quiz #2. The quiz will cover todays lecture (Chapter 2). Password: bacteria You will have up to 2 attempts on the quiz, your highest attempt will be graded. The quiz is open note, book, and slide(s) you may also work in teams. No searching up of questions/answers. Homework 1 (unlimited attempts), Laboratory Safety, Getting Started, and Microbiology Laboratory Preparation (HOL’s) are all due Sunday at/by 11:59pm © 2018 Pearson Education, Inc.