Bacteria

BACTERIABACTERIA

The Oldest Living Structures The Oldest Living Structures on the Earth!on the Earth!

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Kingdom ArchaebacteriaKingdom Archaebacteria

Most inhabit extreme environments on Most inhabit extreme environments on the earth. There are THREE main the earth. There are THREE main groupings.groupings.– MethanogensMethanogens

Are anaerobic and live in swamps, marshes, the Are anaerobic and live in swamps, marshes, the guts of animals, and sewage treatment pondsguts of animals, and sewage treatment ponds

– Extreme HalophilesExtreme Halophiles Live in high salt areas such as the Dead Sea Live in high salt areas such as the Dead Sea

and the Great Salt Lakeand the Great Salt Lake

– Extreme ThermophilesExtreme Thermophiles Live in hot springs with temperatures of 60Live in hot springs with temperatures of 60ooC to C to

8080ooCC Cell walls do not contain peptidoglycanCell walls do not contain peptidoglycan

Kingdom EubacteriaKingdom Eubacteria

ProkaryoticProkaryotic Includes the spirochetes, gram-Includes the spirochetes, gram-

positive bacteria and cyanobacteriapositive bacteria and cyanobacteria Live just about anywhereLive just about anywhere Have a cell wall that contains Have a cell wall that contains

peptidoglycan (carbohydrate)peptidoglycan (carbohydrate)

Kingdom ComparisonKingdom Comparison

EUBACTERIEUBACTERIAA

ARCHAEBACTERIARCHAEBACTERIAA

Nuclear Nuclear EnvelopeEnvelope

AbsentAbsent AbsentAbsent

Membrane Membrane OrganellesOrganelles

AbsentAbsent AbsentAbsent

PeptoglycaPeptoglycan Cell Walln Cell Wall

PresentPresent AbsentAbsent

RibosomesRibosomes PresentPresent PresentPresent

Size RelationshipsSize Relationships

10 Microns10 Microns Virus (.05 – 1 micron)Virus (.05 – 1 micron) Bacteria (.05 – 1.5 Bacteria (.05 – 1.5

microns)microns) Red blood cell (5 Red blood cell (5

microns)microns) White blood cell (5-8 White blood cell (5-8

Microns)Microns) Sperm (60 microns)Sperm (60 microns)

Bacterial ShapesBacterial Shapes

Bacillus bacteria are rod Bacillus bacteria are rod shapedshaped

Cocci bacteria are roundCocci bacteria are round

Spirillum are spiral Spirillum are spiral shapedshaped

Groupings of BacteriaGroupings of Bacteria

IndividualIndividual

Diplo – in pairsDiplo – in pairs

Strepto – in chainsStrepto – in chains

Staphlo – clustered like grapesStaphlo – clustered like grapes

IdentificationIdentification Gram StainGram Stain

– The gram stain differentiates bacteria on The gram stain differentiates bacteria on the basis of structure and composition the basis of structure and composition of the layers of the cell wall. of the layers of the cell wall.

– After staining:After staining: Gram positive bacteria appear purpleGram positive bacteria appear purple Gram negative bacteria appear pink.Gram negative bacteria appear pink.

– Cell walls have a simpler structure than Cell walls have a simpler structure than gram negative cell walls gram negative cell walls

Gram StainGram Stain

General StructureGeneral Structure

Nearly all Nearly all prokaryotes have prokaryotes have cell wallscell walls

Bacteria have one Bacteria have one major chromosome major chromosome and rings of DNA and rings of DNA called plasmidscalled plasmids

Ribosomes are Ribosomes are present to help in present to help in protein formationprotein formation

General StructureGeneral Structure

Many disease Many disease causing causing bacteria have bacteria have a thick outer a thick outer slime capsule slime capsule for protectionfor protection

Many bacteria Many bacteria have small have small hair-like pili to hair-like pili to attach to other attach to other cellscells

Peptidoglycan

Cell wall

Cell membrane

Ribosome

Flagellum DNA Pili

Bacteria Cell StructureBacteria Cell Structure

Single cellSingle cell Nucleoid (plasmid)Nucleoid (plasmid)

– Area where single DNA strand is foundArea where single DNA strand is found FlagellaFlagella

– For movementFor movement Capsule (Peptidoglycan)Capsule (Peptidoglycan)

– Coating on outside of cell wallCoating on outside of cell wall

Bacteria Cell StructureBacteria Cell Structure Cell WallCell Wall

– Tough, rigid structure for support, shape Tough, rigid structure for support, shape and protectionand protection

– Main function – prevent osmotic ruptureMain function – prevent osmotic rupture– Water always moving in cell, so if cell Water always moving in cell, so if cell

wall OK, cell is OKwall OK, cell is OK– Bacteria growing in Penicillin grow holes Bacteria growing in Penicillin grow holes

in their cell walls, rupture, and diein their cell walls, rupture, and die Cell membraneCell membrane Ribosomes for making proteinsRibosomes for making proteins

Bacteria Cell StructureBacteria Cell Structure

Cells Alive:Cells Alive: http://www.cellsalive.com/cells/bactcell.htmhttp://www.cellsalive.com/cells/bactcell.htm

Bacterial ReproductionBacterial Reproduction

ProkaryotesProkaryotes– Reproduce asexually by binary fission Reproduce asexually by binary fission

(cell splits apart)(cell splits apart)– Continually making new DNA in good Continually making new DNA in good

conditionsconditions– In bad conditions, form In bad conditions, form endosporeendospore

Internal resting cell that surrounds the DNA, Internal resting cell that surrounds the DNA, some cytoplasm, and thick outer coatsome cytoplasm, and thick outer coat

May live in for long timeMay live in for long time

Bacterial ReproductionBacterial Reproduction

Genetic Information Exchanged 3 Genetic Information Exchanged 3 WaysWays– TransformationTransformation

Genes taken up from the surrounding Genes taken up from the surrounding environmentenvironment

– ConjugationConjugation Genes are transferred from cell to cell Genes are transferred from cell to cell

(sexually—through a tube)(sexually—through a tube)

– TransductionTransduction Genes are transferred between prokaryotes Genes are transferred between prokaryotes

by virusesby viruses

Bacterial Population GrowthBacterial Population Growth

Click on the icon above. Upon Click on the icon above. Upon viewing the dividing bacteria, take viewing the dividing bacteria, take note of the FOUR stages of the note of the FOUR stages of the population growth curvepopulation growth curve

Aerobic vs. AnaerobicAerobic vs. Anaerobic

AerobicAerobic– Obligate aerobesObligate aerobes

Must have oxygen Must have oxygen present to livepresent to live

AnaerobicAnaerobic– Obligate anaerobesObligate anaerobes

Must live where Must live where there is no oxygenthere is no oxygen

Get energy from Get energy from fermentationfermentation

– Faculative anaerobes Live where there is

oxygen Live where there is

no oxygen

Bacterial NutritionBacterial Nutrition

AutotrophsAutotrophs– Make own foodMake own food– Smelly food caused Smelly food caused

by bacteria that are by bacteria that are making food from making food from substances that substances that have sulfur or ironhave sulfur or iron

HeterotrophsHeterotrophs– DecomposersDecomposers

Feed on dead plants Feed on dead plants and animalsand animals

Usually do not cause Usually do not cause diseasedisease

Ex: Nitrogen CycleEx: Nitrogen Cycle

– ParasitesParasites Live on or in living Live on or in living

organismsorganisms Can cause diseaseCan cause disease

Economic Importance of Economic Importance of BacteriaBacteria

Nitrogen FixationNitrogen Fixation– All organisms need nitrogen to make All organisms need nitrogen to make

proteinsproteins– Bacteria convert nitrogen to a form Bacteria convert nitrogen to a form

organisms can useorganisms can use Recycling of NutrientsRecycling of Nutrients

– Necessary to breakdown the organic Necessary to breakdown the organic matter in dead organisms and wastes, matter in dead organisms and wastes, returning nutrients to the soilreturning nutrients to the soil

Economic Importance of Economic Importance of BacteriaBacteria

FoodFood– Breakdown chemicals for their food by Breakdown chemicals for their food by

fermentationfermentation– Release other molecules we use Release other molecules we use

because of distinct flavors and aromas because of distinct flavors and aromas (cheese, yogurt, sauerkraut)(cheese, yogurt, sauerkraut)

MedicinesMedicines– Produce antibiotics which kill other Produce antibiotics which kill other

bacteriabacteria

Economic Importance of Economic Importance of BacteriaBacteria

DiseaseDisease– Only a fewOnly a few– About half of all human diseases are About half of all human diseases are

caused by bacteriacaused by bacteria

Food Bourne Bacteria Food Bourne Bacteria Can Harm YouCan Harm You

BotulismBotulism SalmonellaSalmonella StaphylococcusStaphylococcus E. ColiE. Coli

StaphylcoccusStaphylcoccus

Staphylcoccus aureusStaphylcoccus aureus

E. Coli bacteriaE. Coli bacteria

What type of Bacteria is What type of Bacteria is this?this?

Staphylcoccus - MRSAStaphylcoccus - MRSA

Bacteria ColoniesBacteria Colonies

This is what we are going to This is what we are going to do.do.