Prokaryote: no nucleus or organelles –Chromosome & plasmids float freely in cytoplasm Ribosomes: create proteins Flagella: used in movement Pili: act as anchors Capsule: outer coating Endospore: “cocoon” to protect DNA in harsh times

Many bacteria grow in colonies 3 Basic Shapes: 1) Bacilli = Rod 2) Coccus = Spherical 3) Spirillum = Spiral

Bacteria Reproduction Binary Fission: asexual reproduction where one cell splits into two cells –Both cells have identical sets of DNA –Less genetic diversity Conjugation: process where DNA is exchanged –Cells connect by pili –DNA exchanged Creates genetic diversity

Nutrition Heterotrophs: feed on matter produced by others –Saprophytes: absorb nutrients from dead matter –Parasites: absorb nutrients from living matter Essential to healthy ecosystems

Obligate Aerobe = must live in oxygen Obligate Anaerobe = cannot live in oxygen Facultative Aerobe = can live with or without oxygen The bacteria that causes TB lives in your lungs… which type is it?

GRAM NEGATIVEGRAM POSITIVEBacteria Common to most environments on Earth Identified by Gram Stain test –Gram negative: stains pink harder to treat –Gram positive: stains purple easier to treat Treatments differ depending upon results

Gram Stain Overview

O2 Cyanobacteria: autotrophic bacteria Evolutionary Importance –Early life lived in oceans (no ozone layer) –Cyanobacteria released O 2 into the atmosphere –O 2 recombined into ozone (O 3 ) in the stratosphere –Protective layer allowed life to evolve on land UV Cyanobacteria in Ocean water Ozone layer (O 3 ) develops over millions of years Uninhabited land UV Bacteria

Helpful Bacteria Helpful in nature –Cyanobacteria: create O2 –Decomposers: recycle C –Nitrogen fixer bacteria Bacteria have been engineered for human uses: –Food: cheese, bread, yogurt, cabbage, sauerkraut –Medicine: antibiotics –Industry: insecticides, fuel, environmental cleanup

Kingdom Bacteria Gram Positive Thinner capsule Stains purple Gram Negative Thicker capsule Stains pink Cyanobacteria Autotrophs Created ozone layer

HEALTHY GINGIVITIS MODERATE PERIODONTITISADVANCED PERIODONTITIS

Salt, heat, & acid loving prokaryotes

Live in extreme environments 1) Methanogens: –Anaerobic –Produce methane gas as a waste product –Habitat: Swamps, sewage, digestive tract

2) Thermophiles Heat and acid loving archaea Habitat: Deep sea vents, volcanoes, hot springs (230°F)

3) Halophiles –Thrive in areas of high salt concentration Salt normally dehydrates organisms –Use salt to make energy

Kingdom Archaea Halophiles thrive in salty environments Methanogens live in anaerobic environments produce methane as waste Thermophiles thrive in extremely hot environments

Name this bacteria shape!

Name these cell parts!

Name the process shown in this animation.

1) What is the main difference between bacteria and all other life on Earth? 2) What is the purpose of… –ribosomes? –pili? –endospores? –capsule? 3) Name the process where bacteria divide themselves? 4) Examine the next slide and identify the cell parts. 5) How do the 3 types of respiration differ among bacteria? 6) Which archaebacteria love salt? 7) How do Gram + and – bacteria differ? 8) Which beneficial gas do cyanobacteria release into the atmosphere? 9) What did this gas eventually create?