Bacteria Chapter 19 Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

The Prevalence of Bacteria Bacteria are the oldest, structurally simplest, and the most abundant forms of life on earth. Abundant for over 2 billion years before the appearance of eukaryotes. 5,000 different kinds currently recognized. Based primarily upon their metabolic and genetic characteristics. Can only be properly characterized on a defined medium. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

The Prevalence of Bacteria Bacterial Form Bacillus (Bacilli) straight and rod-shaped. Coccus (Cocci) spherical shaped. Spirillus (Spirilla) long and helical shaped. Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

The Prevalence of Bacteria Prokaryotes versus Eukaryotes Multicellularity Cell Size Chromosomes Cell Division and Recombination Internal Compartmentalization Flagella Metabolic Diversity Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Usually consist of peptidoglycan. The Bacterial Surface Bacterial Surface Cell wall maintains shape and protects the cell from swelling and rupturing. Usually consist of peptidoglycan. Gram Positive - Thicker peptidoglycan Gram Negative - Thinner peptidoglycan Flagella - Slender protein - locomotion Pili - Hairlike structures - attachment Endospores - Resistant to environment. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Gram Stain Copyright © McGraw-Hill Companies Permission required for reproduction or display Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Invaginated plasma membrane. Nucleoid Region The Cell Interior Internal Membranes Invaginated plasma membrane. Nucleoid Region Lack nucleus - Genes encoded with single double-stranded DNA. Ribosomes Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Key Classification Characteristics Photosynthetic or Nonphotosynthetic Bacterial Diversity Key Classification Characteristics Photosynthetic or Nonphotosynthetic Motile or Nonmotile Unicellular or Multicellular Spore Formation by Division or Transverse Binary Fission. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Comparing Archaebacteria and Eubacteria Cell Wall Bacterial Diversity Comparing Archaebacteria and Eubacteria Cell Wall Archaebacteria lack peptidoglycan. Plasma Membranes Composed of different lipids. Gene Translation Machinery Archaebacteria similar to eukaryotes. Gene Architecture Eubacteria not interrupted by introns. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Two Process create bacterial variation: Mutation Spontaneous errors in DNA replication. Genetic Recombination Occurs by gene transfer from one cell to another by viruses or conjugation. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Obtain carbon from inorganic CO2. Photoautotrophs - Sunlight Bacterial Metabolism Autotrophs Obtain carbon from inorganic CO2. Photoautotrophs - Sunlight Chemoautotrophs - Inorganic Chemicals Heterotrophs Obtain carbon from organic molecules. Photoheterotrophs - Sunlight Chemoheterotrophs - Organic Molecules Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

How Heterotrophs Infect Host Organisms Bacterial Metabolism How Heterotrophs Infect Host Organisms Proteins secreted by Type III System. May be used to transfer other virulence proteins into nearby eukaryotic cells. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Human Bacterial Diseases Tuberculosis Afflicts respiratory system and easily transmitted from person to person through the air. Dental Caries (cavities) Tooth decay caused by bacteria present in plaque. High sugar diets increase tooth decay. Lactic acid bacteria ferment sugars and reduce pH, thus degenerating tooth enamel. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Human Bacterial Diseases Sexually Transmitted Diseases Gonorrhea (Neisseria gonorrhoeae) Syphilis (Treponema pallidum) Chlamydia (Chlamydia trachomatis) Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Importance of Bacteria Largely responsible for creating atmospheric properties. Contribute to carbon balance. Nitrogen Fixation Industrial Processes Fermentation of lactose into lactic acid. Milk, Cheese, Yogurt Genetic Engineering Removal of environmental pollutants. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies

Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies