BacteriaBacteria

Bacterial HistoryBacterial History

The first cells in existenceThe first cells in existence Fossils exist for prokaryotes 3.5 billion Fossils exist for prokaryotes 3.5 billion

years agoyears ago Most bacteria autotrophicMost bacteria autotrophic PathogenicPathogenic bacteria make up only a bacteria make up only a

small percentage of total bacterial small percentage of total bacterial speciesspecies

ClassificationClassification

Separated into two kingdoms based on Separated into two kingdoms based on rRNA sequencingrRNA sequencing Archea/ArchaebacteriaArchea/Archaebacteria Bacteria/EubacteriaBacteria/Eubacteria

Traditionally grouped by structure and Traditionally grouped by structure and physiology, and reaction to stainsphysiology, and reaction to stains

ArcheabacteriaArcheabacteria

Cell walls contain no Cell walls contain no peptidoglycan, do peptidoglycan, do contain special lipidscontain special lipids

First found in First found in Extreme Extreme environments, but environments, but now found now found everywhereeverywhere

ArcheabacteriaArcheabacteria

Three Major TypesThree Major Types Methanogens- harvest energy by converting Methanogens- harvest energy by converting

CO2 and H2 into methane gasCO2 and H2 into methane gas Extreme Halophiles- Salt loving bacteria, Extreme Halophiles- Salt loving bacteria,

use the difference in concentration to use the difference in concentration to generate ATPgenerate ATP

Thermoacidophiles- Live in very hot very Thermoacidophiles- Live in very hot very acidic places, like near underwater volcanic acidic places, like near underwater volcanic ventsvents

Eubacteria Eubacteria

Have one of three Have one of three major shapesmajor shapes CocciCocci BacilliBacilli SpirillaSpirilla

Eubacteria- Gram Eubacteria- Gram StainingStaining

Process designed to Process designed to differentiate between cell differentiate between cell wall typeswall types

GramGram Positive Positive PurplePurple Thick peptidoglycan Thick peptidoglycan

LayerLayer Gram NegativeGram Negative

PinkPink Thin peptidoglycan Thin peptidoglycan

layerlayer Double lipid membraneDouble lipid membrane