Chapter 10 Bacteria & Viruses

Chapter 10A 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). True 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

REPRODUCTION AND GROWTH 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 pH 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