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Bacteria
Teeny Meanies or Good Guys?!
Living Things Review
• All living things fall into one of five
Kingdoms:
– Monera (bacteria)
– Protista (protists)
– Fungi (fungus)
– Plantae (plants)
– Animalia (animals)
Our Very First Kingdom!
• Kingdom Monera
– aka Bacteria
Eubacteria
• Made up of two kinds of bacteria:
– Eubacteria
– Archaebacteria
Archaebacteria
Archaebacteria stain in Geyser Basin
Characteristics of Bacteria
• All are single-celled
• No Nucleus - they are prokaryotes!
• Have three main shapes
– Bacilli
– Cocci
– Spirilla
Bacteria Shapes
• Each shape helps the bacteria in a
different way
• Bacilli - rod shaped
• Cocci - spherical
• Spirilla - long and spiral shaped
Flagella
• Whip-like structure
• On the outside of the
cell
• Helps move through
fluids
Bacterial Reproduction: Binary
Fission
• Binary Fission - one single-celled bacteria
splits into two single-celled bacteria
– Four steps
• DNA is in circular loops
** Each new cell has one exact copy of the parent
cell’s DNA
Binary Fission Diagram
Bacteria Mini-Quiz
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What are the five kingdoms of living things?
What are two different kinds of bacteria?
What are the three shapes of bacteria?
What is a flagella?
What kind of reproduction do bacteria
undergo?
• What is the shape of bacterial DNA?
Bacteria’s Special Adaptation
• Bacteria like warm, moist places to live
• When it gets too dry or cold, bacteria form
endospores
• Endospore - a thick-walled protective spore
that forms inside a bacterial cell and resists
harsh conditions
• When conditions improve, the endospores
break open and bacteria become
active again.
Eubacteria
• Eubacteria - true bacteria
– Make up most of the bacteria kingdom
– Has more individual species than all of the
other five kingdoms combined
– Classified by the way they get food
• Consumers (eat other organisms)
• Decomposers (feed on dead things)
• Producers (use sun to make food; are green)
Cyanobacteria
• Special kind of eubacteria that contains
chlorophyll (just like plants!)
• Producer
• Green, Blue or Red
• Usually live in water
Archaebacteria
• Archaebacteria - ancient bacteria
• Chemically different from Eubacteria
– Lack peptidoglycan in their cell membrane
• Three types:
– Heat lovers
– Salt lovers
– Methane makers (ew!!)
• Live in harsh environments where nothing
else can survive
– Prefer little/no oxygen present
Archaebacteria - Heat Lovers
• Thermophiles (heat lover)
• Live in ocean vents and hot springs
• Usually live in water from 60oC to 80oC
Archaebacteria - Salt Lovers
• Halophiles (salt lovers)
– Live in very salty environments like the
Dead Sea and Great Salt Lake
Archaebacteria - Methane
Makers
• Methanogens (methane makers)
– Give off methane gas
– Live in swamps and animal intestines
– STINK!!!!
Bacteria’s Role in the World
Are they Good or Bad??
(BOTH!)
Good for the Environment
Nitrogen Fixation: bacteria convert nitrogen in the
air into a form of nitrogen that plants can use
Recycling: bacteria break down dead plants and
animals into nutrients for other living things
Cleaning Up: bacteria are used to fight pollution
• Bioremediation: using microorganisms to change harmful
chemicals into harmless ones
• Ex: used to clean up oil spills or remove pollutants from the soil
Good for People
Bacteria in your food: bacteria
converts milk sugar into lactic acid,
which adds flavor and preserves food
ex.) yogurt, sour cream, cheese
Making medicines: some bacteria
make you sick; other bacteria can
make you well!
antibiotics: medicines used to kill
bacteria; many are made by bacteria!
Good for People
Insulin: bacteria can make insulin and
then doctors give that insulin to people
with diabetes
Genetic Engineering: changing the
genes of a living thing.
– Scientists have made things such as
insecticides, cleansers and adhesives
Harmful Bacteria
• Pathogenic bacteria - bacteria that
cause disease
– Can be treated with antibiotics
• Anti = against
• Biotic = living thing
– Can attack plants, animals, protists, fungi
and even other bacteria!