Bacteria & ArchaeaBacteria & Archaea

• 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”

that forms around DNA to protect in harsh times

• Many bacteria grow in colonies

• 3 Basic Shapes:

• 1) Bacilli/Bacillus = Rod• 2) Cocci/Coccus = Spherical• 3) Spirilla/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?

O2O2 O2 O2

• Cyanobacteria: autotrophic bacteria• Evolutionary Importance

– Early life lived in oceans (no ozone layer)

– Cyanobacteria released O2 into the atmosphere

– O2 recombined into ozone (O3) in the stratosphere

– Protective layer allowed life to evolve on land

UV

UV

Cyanobacteria in Ocean water

Ozone layer (O3) develops over millions of years

Uninhabited land

UV

UVUV

UVBacteriaBacteria

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,

sauerkraut

– Medicine: antibiotics

– Industry: insecticides, fuel, environmental cleanup

GRAM NEGATIVE GRAM POSITIVE

Identifying Bacteria Identifying Bacteria • 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

Kingdom Bacteria

Gram Positive

• Thinner capsule• Stains purple

Gram Negative

• Thicker capsule• Stains pink

Cyanobacteria

• Autotrophs• Created ozone layer

HEALTHY GINGIVITIS

MODERATE PERIODONTITIS ADVANCED PERIODONTITIS

Salt, heat, & acid loving prokaryotes

• Live in extreme environments• 1) Methanogens:

– Anaerobic (Obligate Anaerobe)– 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

Silly…yet educational…Archaea AKA Archaebacteria

Name this bacteria shape!

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?