1 1 Prokaryotes Prokaryotes - Outline • Prevalence of Prokaryotes • Structure • Metabolic Diversity • Eubacteria and Archaebacteria • Classification of Prokaryotes • Examples of Prokaryotes & Diseases • Benefits of Prokaryotes The First Cells Rocks 3.5- 3.8 billion yrs old Microfossils prokaryote like Living cyanobacteria Shark Bay, Australia Green River, Wyoming Comparison of Eukaryotes & Prokaryotes No Yes True nucleus Prokaryotes Eukaryotes Characteristic 0.2 – 2 um > 10 um Cell Size Naked, circular DNA + Histones Chromosomes Transformation Conjugation Meiosis Genetic recombination No Yes and No Multicellularity Naked circular DNA + Histones Chromosomes Binary fission Mitosis Cell division No Yes Internal Compartments Single flagellin fiber Spinning movement 9+2 microtubules Whiplike movement Flagella
14
Embed
Prokaryotes Prokaryotes - Outline • Prevalence of ... · Prokaryotes Prokaryotes ... Living cyanobacteria Shark Bay, Australia Green River, Wyoming ... • Economic Importance –
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
1
Prokaryotes Prokaryotes - Outline• Prevalence of Prokaryotes• Structure• Metabolic Diversity• Eubacteria and Archaebacteria• Classification of Prokaryotes• Examples of Prokaryotes & Diseases• Benefits of Prokaryotes
The First Cells
Rocks 3.5- 3.8 billion yrs oldMicrofossils prokaryote like
Living cyanobacteria
Shark Bay, Australia
Green River, Wyoming
Comparison of Eukaryotes & Prokaryotes
NoYesTrue nucleus
ProkaryotesEukaryotesCharacteristic
0.2 – 2 um> 10 umCell Size
Naked, circular DNA+ HistonesChromosomes
TransformationConjugation
MeiosisGenetic recombination
NoYes and NoMulticellularity
Naked circular DNA+ HistonesChromosomes
Binary fissionMitosisCell division
NoYesInternal Compartments
Single flagellin fiber Spinning movement
9+2 microtubulesWhiplike movement
Flagella
2
Prokaryotic Features - Mechanisms of diversity
-Transformation = Pick up DNA from the environment-Conjugation = Cell-to-cell DNA transfer-Transduction = DNA transfer by bacteriophages
Sources spontaneously exposure to radiationexposure to chemicals
How often do bacteria mutate? E. coli has 5000 genes 1 mutation/million genes.
… 1 mutation in 200 bacteria… 1 billion bacteria in 1 spoonful of soil… 5 million mutant bacteria in 1 spoonful of soil!
1. Mutation
2. Horizontal gene transfer
Prokaryotic Diversity Horizontal Gene Transfer
2. Transduction by bacteriophage
3. Conjugation & plasmid transfer
Conjugation bridge
1. Transformation
Negative consequences for humansMRSA - Methicillin-resistant Staphylococcus aureus
VRSA - Vancomycin-resistant Staphylococcus aureus
E.coli 157:H7 – harmful traits acquired by transduction & conjugation
Prokaryotes the oldest – 3.5 billion years oldsimplest forms of lifeubiquitous 5,000 – 50,000 species
Less than 10% of species are known
Early classification characteristics of prokaryotesEnergy metabolismMotilityUnicells, colonies or filamentsSpore formationImportance as human pathogens or not