Chapter 10 Bacteria Viruses Chapter 10 A Bacteria

Chapter 10 Bacteria & Viruses

Chapter 10 A Bacteria

Characteristics of Bacteria • Very small, but largest in number • Hard to study • Can live almost anywhere • Prokaryotic

Microbiology The study of microbes (organisms that require a microscope to be seen)

Most bacteria are pathogenic (cause disease). 1. True 2. False

Pathogenic: causing disease; bacteria and viruses Decomposers: organisms that break down organic substances; bacteria and fungi

Kingdom Archaebacteria • Cell walls DO NOT contain peptidoglycan • “Extremophiles” –Thermoacidophiles –Methanogens –Halophiles

Kingdom Eubacteria • The larger kingdom • Contains the bacteria people are most familiar with • Cell walls DO contain peptidoglycans • Very diverse

Bacterial Shapes • Coccus: spherical • Bacillus: rod-shaped • Spirillum: spiral-shaped

Uses of Bacteria • Most bacteria are NOT pathogenic. • Used in making cheese, yogurt, sauerkraut, and buttermilk • Form alcohol, lactic acid, and vinegar through fermentation

Uses of Bacteria • Used in tanning leather and forming silage • Help break down food in the intestines • Source of antibiotics

Uses of Bacteria • Through genetic engineering techniques, bacteria can be used to produce: – human insulin – blood proteins – other substances

Uses of Bacteria • Bacteria and fungi are the primary decomposers in nature. • The process of bioremediation uses bacteria to break down harmful substances in the environment.

Structure of a Bacterial Cell • Prokaryotic • Plasma (cell) membrane • Cell wall –Peptidoglycans –Gram’s staining • Capsule

Structure of a Bacterial Cell • Nuclear area • Plasmids • Mesosomes • Ribosomes • Flagella

BACTERIAL REPRODUCTION AND GROWTH Reproduction is by simple binary fission that does NOT involve mitosis.

Transfer of Genetic Material • Conjugation • Transformation • Transduction

Bacteria and Nutrition • Autotrophic (some bacteria) – Photosynthetic – Chemosynthetic (converting inorganic compounds into usable forms)

Bacteria and Nutrition • Heterotrophic (most bacteria) – Saprophytic – Parasitic • Obligate parasites

Bacteria and Nutrition Heterotrophic Autotrophic Saprophytic Parasitic Photosynthetic Chemosynthetic

Conditions for Bacterial Growth • Moisture • Temperature • p. H • Nutrition

Endospores: special spores produced by some bacteria that allow them to survive long periods of unfavorable growing conditions Ex: the bacterium that causes anthrax

Bacteria and Oxygen • Obligate anaerobes • Obligate aerobes • Facultative anaerobes

Other Bacteria • Rickettsiae –Intracellular parasites –Typhus fever –Rocky Mountain spotted fever

Other Bacteria • Spirochetes –Larger than most bacteria –Many are corkscrew-shaped –Lyme disease

Other Bacteria • Mycoplasmas –No cell wall –Some types of pneumonia, arthritis, and urinary tract infections