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Bacteria
What you need to know!!!!
What are Bacteria?
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They are prokaryotes that have cell walls
containing peptidoglycans.
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Prokaryotes: Organisms who’s cells lack a
nucleus
Classifying Prokaryotes
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2 main types
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1. Eubacteria
2. Arachebacteria
Eubacteria
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Live almost everywhere
Have a cell wall
Have a cell membrane
Have cytoplasm
No nuclei
Archebacteria
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Live in extreme environments
Have a cell wall
No nuclei
How do we identify Bacteria?
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Shape
Cell wall
How they move
How they get energy
Bacteria Shapes
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Rod shaped: Bacilli
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Spherical shaped: Cocci
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Spiral or Corkscrew: Spirilla
Cell walls
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2 Different ones in Eubacteria
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1. Gram-positive: Purple when viewed under a
microscope
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2. Gram-Negative: Light pink or red when
viewed
How They Move
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Some don’t move at all
Some have Flagella: a small whip-like
structure that makes the bacteria move
forward.
Some snake or spiral forward
Some glide along slowly
How do They Obtain Energy?
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2 Main ways
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1. Heterotrophs: They get energy by eating
other organic molecules
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2. Autotrophs: They make their own food from
inorganic molecules
Types of Bacterial Heterotrophs
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Chemoheterotrophs: Take in organic
molecules for both energy and carbon
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Photoheterotrophs: They are
photosynthetic but still need organic
compounds as a carbon source.
Types of Bacterial Autotrophs
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Photoautotrophs: Uses light energy to
convert carbon dioxide and water to carbon
compounds.
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Chemoautotrophs: Makes organic carbon
molecules from CO2 using energy from
chemical reactions.
How do Bacteria Release Energy?
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They use either cellular Respiration or
Fermentation.
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Cellular Respiration: Releasing energy by
breaking down glucose and other food molecules
using oxygen.
Fermentation: Cells release energy in the
absence of oxygen.
Different types of Bacterial
Respiration
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Obligate Aerobes: Bacteria that must have
a constant supply of oxygen in order to live.
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Obligate Anaerobe: Bacteria that does not
need oxygen in order to survive.
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Facultative Anaerobes: Bacteria that can
survive with or without oxygen.
Growth and Reproduction of
Bacteria
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Bacteria grow and divide at astonishing
rates!
Types:
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Binary Fission
Conjugation
Spore Formation
Growth and Reproduction of
Bacteria Continued…
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Binary Fission: Type of asexual reproduction in
which a bacteria replicates its DNA and divides in
half, producing two identical daughter cells.
Conjugation: Sexual reproduction between two
bacterial cells. They exchange genetic
information.
Spore Formation: Used to save itself in
unfavorable conditions.
How we use Bacteria for help!!
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Decompose dead matter and organisms
To preserve food and beverages
Yogurt
Intestinal bacteria to help us digest food
The END!!!!!