Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation prepared by Christine L. Case Microbiology B.E Pruitt & Jane J. Stein AN INTRODUCTION EIGHTH EDITION TORTORA FUNKE CASE Chapter 2, part B Chemical Principles

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Important Biological Molecules Organic compounds always contain carbon and hydrogen. Inorganic compounds typically lack carbon.

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Polar molecule Inorganic Compounds: Water Figure 2.4a

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Solvent Polar substances dissociate, forming solutes Inorganic Compounds: Water Figure 2.5

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings H + and OH  participate in chemical reactions Inorganic Compounds: Water

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hydrogen bonding between water molecules makes water a temperature buffer. Inorganic Compounds: Water Figure 2.4b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings An acid is a substance that dissociates into one or more H +. HCl  H + + Cl  Acids, Bases, and Salts Figure 2.6a

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings A base is a substance that dissociates into one or more OH . NaOH  Na + + OH  Acids, Bases, and Salts Figure 2.6b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings A salt is a substance that dissociates into cations and anions, neither of which is H + or OH . NaCl  Na + + Cl  Acids, Bases, and Salts Figure 2.6c

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The amount of H + in a solution is expressed as pH. pH =  log[H + ] Increasing [H + ], increases acidity. Increasing [OH  ] increases alkalinity. Most organisms grow best between pH 6.5 and 8.5. Acid-Base Balance

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Acid-Base Balance Figure 2.7

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The chain of carbon atoms in an organic molecule is the carbon skeleton. Functional groups are responsible for most of the chemical properties of a particular organic compound. Organic Compounds

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Table 2.3.1

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Small organic molecules can combine into large macromolecules. Macromolecules are polymers consisting of many small repeating molecules. The smaller molecules are called monomers. Organic Compounds

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Monomers join by dehydration synthesis or condensation reactions. Organic Compounds Figure 2.8

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Are important for structure and as energy sources. Consist of C, H, and O with the formula (CH 2 O) n Carbohydrates Figure 2.8

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Monosaccharides are simple sugars with 3 to 7 carbon atoms. Carbohydrates Figure 2.8

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Disaccharides are formed when two monosaccharides are joined in a dehydration synthesis. Disaccharides can be broken down by hydrolysis. Carbohydrates Figure 2.8

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Oligosaccharides consist of 2 to 20 monosaccharides. Polysaccharides consist of tens or hundreds of monosaccharides joined through dehydration synthesis. Starch, glycogen, dextran, and cellulose are polymers of glucose that are covalently bonded differently. Chitin is a polymer of two sugars repeating many times. Carbohydrates

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Are the primary components of cell membranes. Consist of C, H, and O. Are nonpolar and insoluble in water. Lipids

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Called fats or triglycerides contain glycerol and fatty acids; formed by dehydration synthesis. Unsaturated fats have one or more double bonds in the fatty acids. Simple lipids Figure 2.9c

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Contain C, H, and O + P, N, or S. Membranes are made of phospholipids Complex lipids Figure 2.10a

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Consist of four carbon rings, with an –OH group attached to one ring. Are part of membranes. Steroids Figure 2.11

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Are essential in cell structure and function. Enzymes are proteins that speed chemical reactions. Transporter proteins move chemicals across membranes. Flagella are made of proteins. Some bacterial toxins are proteins. Proteins

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Consist of subunits called amino acids. Proteins Table 2.4.1

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Proteins Table 2.4.2

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Exist in either of two stereoisomers, D or L. L -forms are most often found in nature. Amino Acids Figure 2.13

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Peptide bonds between amino acids are formed by dehydration synthesis. Peptide Bonds Figure 2.14

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The primary structure is a polypeptide chain Levels of Protein Structure Figure 2.15a

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The secondary structure occurs when the amino acid chain folds and coils in a regular helix or pleats. Levels of Protein Structure Figure 2.15b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The tertiary structure occurs when the helix folds irregularly, forming disulfide bonds, hydrogen bonds, and ionic bonds between amino acids in the chain. Levels of Protein Structure Figure 2.15c

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The quaternary structure consists of two or more polypeptides. Levels of Protein Structure Figure 2.15d

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Conjugated proteins consist of amino acids and other organic molecules: Glycoproteins Nucleoproteins Lipoproteins Level of Protein Structure

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Consist of nucleotides. Nucleotides consist of a: Pentose Phosphate group Nitrogen-containing (purine or pyrimidine) base Nucleic Acids Figure 2.16

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Has deoxyribose Exists as a double helix A hydrogen bonds with T C hydrogen bonds with G DNA Figure 2.16

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Has ribose Is single-stranded A hydrogen bonds with U C hydrogen bonds with G RNA Figure 2.17

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Has ribose, adenine, and 3 phosphate groups ATP Figure 2.18

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Is made by dehydration synthesis. Is broken by hydrolysis to liberate useful energy for the cell. ATP