Bacteria
Lots of Them
Prokaryotes are Earth’s most abundant life forms. •
They can survive in many environments. •
They can get energy from many different sources. •
Prokaryote characters
Mostly single-celled •
No nucleus or organelles •
Circular chromosomes •
Cell walls •
Reproduce mostly asexually •
Anaerobic or aerobic •
Heterotrophic or autotrophic •
2 TYPES OF BACTERIA
Bacteria •
-Get food from an outside source
Blue-green Bacteria •
-Make their own food
Bacteria - small one celled monerans
Bacteria like a warm, dark, and moist environment 
They are found almost everywhere:
-food
-soil
-inside the body -skin
-on most objects
-air
-water
3 Shapes of Bacteria
Bacteria are classified by shape into 3 groups
Spiral:
spirilla
rod-shaped: bacilli, bacillus
Round:
cocci
7 Major Structures of a Bacteria Cell
Capsule
Cell wall
Ribosomes
Nucleoid
Flagella
Pilli •
Cytoplasm
•
•
Capsule
keeps the cell from drying out and helps it stick to food or other 
cells
Cell wall 
Thick outer covering that maintains the overall shape of the 
bacterial cell
Ribosomes 
cell part where proteins are made 
Ribosomes give the cytoplasm of bacteria a granular appearance in 
electron micrographs
Nucleoid
a ring made up of DNA
Flagella
a whip-like tail that some bacteria have for locomotion
Pilli
hollow hair-like structures made of protein 
allows bacteria to attach to other cells. 
Pilli-singular 
Pillus-plural 
Cytoplasm 
clear jelly-like material that makes up most of the cell
Reproduction of Bacteria
Binary Fission- the process of one organism dividing into two
organisms
Fission is a type of asexual reproduction
•
•
•
Asexual reproduction- reproduction of a living thing from only
one parent
The one main (circular) chromosome makes a copy of itself •
Then it divides into two •
The time of reproduction depends on how desirable the conditions
are
Bacteria can rapidly reproduce themselves in warm, dark, and
moist conditions
Some can reproduce every 20 minutes
•
one million bacteria in six (one bacteria could be an ancestor to
hours)
Bacterial Cell &
Nucleiod DNA Ring
DNA replication
Cell wall synthesis
Cell separation
20
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•
Bacteria survival
Endosporea thick celled structure that forms inside the cell •
they are the major cause of food poisoning •
allows the bacteria to survive for many years •
they can withstand boiling, freezing, and extremely dry conditions •
it encloses all the
nuclear materials
•
and some cytoplasm
highly resistant structures 
Bacteria Survival – Food sources
parasites – bacteria that feed on living things
saprophytes – use dead materials for food (exclusively)
decomposers – get food from breaking down dead matter into
simple chemicals
important- because they send minerals and other 
materials back into the soil so other organisms can use
them
Harmful Bacteria 
some bacteria cause diseases •
Animals can pass diseases to humans •
Communicable Disease –
Disease passed from one organism to another
This can happen in several ways:
Air •
Touching clothing, food, silverware, or toothbrush •
Drinking water that contains bacteria
•
BLUE-GREEN BACTERIA •
Autotrophs – make their own food through photosynthesis
•
larger than most bacterial cells 
commonly grow on water and surfaces that stay wet…such as 
rivers, creeks and dams
Some live in salt water, snow, and acid water of hot springs 
food source for animals that live in the water 
BACTERIA BLUE-GREEN 
can be toxic to humans and animals 
Blooms occur when the bacteria multiplies in great numbers
and form scum on the top of the water
Classification of Bacteria
Archaebacteria: extremists •
Eubacteria:
Heterotrophs
•
–
Photosynthetic autotrophs
–
Chemosynthetic autotrophs
–
Archaebacteria
Live in extreme locations: •
Oxygen-free environments –
Concentrated salt-water –
Hot, acidic water –
Eubacteria - Heterotrophs
Found everywhere •

Parasites: live off of other organisms •
Saprobes: live off of dead organisms or waste (recyclers) •
Eubacteria: Photosynthetic Autotrophs
Photosynthetic: make their own food from light •
Cyanobacteria: blue-green, yellow, or red •
ponds, streams, moist areas •
Eubacteria: Chemosynthetic Autotrophs
Get energy by breaking down inorganic substances like sulfur and
nitrogen
Make nitrogen in the air usable for plants
Arrangement
Paired: diplo
•
Grape-like clusters: staphylo
•
Chains: strepto
Shape
Rod: bacillus
•
Spheres: coccus
Spirals: spirillum
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