BacteriaBacteria

Dated back about 3.5 Dated back about 3.5 billion years agobillion years ago

Bacterial CharacteristicsBacterial Characteristics

All prokaryoticAutotrophic or HeterotrophicAverage size- 1um -500um

Kingdom ArchaebacteriaKingdom Archaebacteria

Typ es o f A rch aeb ac te ria

E xtrem e H a lop h iles

S a lt-lovin g

M eth an og en s

C on vert h yd rog en g as & carb on d ioxid e to m eth an e

Th erm oac id op h iles

H ig h tem p era tu re &h ig h ac id ity

K in g d om A rch aeb ac te ria

Kingdom EubacteriaKingdom Eubacteria

Phylum CyanobacteriaPhylum Cyanobacteria - (blue-green algae) photosynthetic

Phylum SpirochetesPhylum Spirochetes - Gram negative, spiral bacteria, heterotrophic, move by a corkscrew rotation (Ex.) syphilis

Phylum ProteobacteriaPhylum Proteobacteria - Largest group, Enteric bacteria, chemoautotrophs, nitrogen-fixing bacteria.

Phylum Gram + bacteriaPhylum Gram + bacteria- Have a thick layer of peptidoglycan.

Bacterial ShapesBacterial Shapes

CocciCocci - round BacilliBacilli - rod SpirilliSpirilli - spiralPrefixes: StaphyloStaphylo-form

clusters StreptoStrepto - form

chains

Bacterial StructureBacterial Structure

DNA (plasmid)Cell MembraneCell Wall

(peptidoglycan) GlycocalyxGlycocalyx -

attachment (sticky) EndosporeEndospore - tough

envelope CapsuleCapsule - protection PiliPili - attachment

Bacterial NutritionBacterial Nutrition

HeterotrophicHeterotrophic - feed on dead, decaying organic matter, called saprophytes.saprophytes.

PhotoautotrophsPhotoautotrophs - use sunlight as a source of energy.

ChemoautotrophsChemoautotrophs - use chemical reactions as a source of energy.

Bacterial RespirationBacterial Respiration

Obligate AnaerobesObligate Anaerobes - cannot live in the presence of oxygen.

Facultative AnaerobesFacultative Anaerobes - can live with or without oxygen.

Obligate AerobesObligate Aerobes - cannot live in the absence of oxygen.

Bacterial ReproductionBacterial Reproduction

Rapid reproductionHeat, cold,

predators, & lack of food inhibitinhibit reproduction.

Methods: Binary fissionBinary fission -

asexual ConjugationConjugation - sexual

Production of ToxinsProduction of Toxins

PathogenPathogen - any organism that causes a disease.

ToxinToxin - Poisonous substances that disrupt the metabolism of the infected organism. EndotoxinEndotoxin - found in the cell wall ExotoxinExotoxin - secreted into areas around

bacteria.

AntibioticsAntibiotics

Inhibit growth of some bacteria.

Disadvantages: Destroy useful

bacteria as well. Resistance of

bacteria.