Bacteria & 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 • 1) Bacilli/Bacillus = Rod
colonies
• 2) Cocci/Coccus = Spherical
• 3 Basic Shapes:
• 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
The bacteria that causes
TB lives in your lungs…
which type is it?
• Obligate Aerobe = must live in oxygen
• Obligate Anaerobe = cannot live in oxygen
• Facultative Aerobe = can live with or without
oxygen
UV
UV
UV
UV
UV UV
Bacteria
• 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
Ozone layer (O3) develops over millions of years
Cyanobacteria in Ocean water
Uninhabited land
O2
O2
O2
O2
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
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 NEGATIVE
GRAM POSITIVE
Gram Stain Overview
Kingdom Bacteria
Gram Positive
Gram Negative
• Thinner capsule
• Stains purple
• Thicker capsule
• Stains pink
Cyanobacteria
• Autotrophs
• Created ozone
layer
HEALTHY
MODERATE PERIODONTITIS
GINGIVITIS
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
Methanogens
Halophiles
• thrive in salty
environments
Thermophiles
• live in anaerobic
environments
• produce methane
as waste
• 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?