Download Bacteria Notes - Sardis Secondary

Kingdom Monera(Archaebacteria &
Eubacteria)
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All bacteria are prokaryotes
Characteristics:
1. No nucleus
2. No membrane bound
organelles
3. Smaller & less ribosomes
4. Most are smaller than
eukaryotes
5. Most are single-celled
organisms
Cell Structure & Function
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Capsule
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Cell Wall
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Gives the cell shape
Prevents osmosis from bursting the cell
Cell Membrane
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Sticky covering on the cell wall
For protection and adherence
Surrounds the cell
Regulates transport
Flagellum
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Whip like protrusion for movement
Cell Structure & Function
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Pili
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Chromosome
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Single DNA molecule
Not contained within a nucleus
Plasmid(s)
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hairlike structures for sticking to another bacteria
during conjugation
Genes located in small circular piece
Ribosomes
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Create protein necessary for life functions
1. Classification by Kingdom
A. Kingdom
Archaebacteria:
• The Extremists
• Harsh environments
• Cell structures differ
from other monerans
B. Kingdom Eubacteria:
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true or traditional
bacteria
2. Classification by Energy Source
A. Autotrophs: organisms
that produce their own
food
i.
Photoautotroph: uses
energy from sun for food
ii. Chemoautotroph(chemosy
nthesizers): obtain energy
from inorganic substances
B. Heterotrophs: organisms that
cannot produce their own food
i.
Photoheterotroph: uses sunlight for
energy but obtains carbon from other
organic source
ii. Chemoheterotroph: obtain energy by
using inorganic molecules and
breaking them down
C. Saprophytes or
Decomposers
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Obtain energy from breaking
down dead organisms
D. Parasites
• Life in/on another organism
host at the expense of the
host but without killing
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Pathogen: any disease causing
bacteria
3. Classification by environment
A. Archaebacteria
1. Methanogens
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Produce methane
Live in swamps, guts of cows & humans
Used to treat sewage & purify water
2. Halophiles
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Live in extremely salty places (eg. Dead
Sea or Salt Lake)
3. Thermoacidophiles
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Live in hot acidic H20 in hot springs
Live in deep sea volcanic vents
Some use inorganic compounds for
energy (chemosynthetic)
B. Eubacteria
1. Heterotrophic bacteria
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Live everywhere
Survive on organic molecules
Some are parasites
Some are saprophytes
2. Photosynthetic Autotrophs
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Cyanobacteria
Perform plant-like photosynthesis
Provide O2 for aquatic environments
3. Chemosynthetic Autotrophs
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Use inorganic compounds for energy
Some convert N2 into N03 for plants
4. Classification by Gram Staining
1. Gram Positive Bacteria
• Cell wall made of protein and
sugar
• Turn purple after gram staining
2. Gram Negative Bacteria
• Extra layer of lipid outside of cell
wall
• Turn pink/red after gram staining
• Require different types of
antibiotics to treat infections
5. Classification by Shapes
1. Spherical (coccus)
• Eg. Streptococcus and Pneumoncoccus
2. Rod-shaped (bacillus)
• Eg. Escherichia coli (E. coli)
3. Spiral (spirillum)
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Eg. Treponema pallidum (syphilis)
Bacterial Shapes
6. Classification by Cellular Respiration
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Process by which nutrients are broken
down to provide energy
A.
Obligate aerobes
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Need oxygen to live (eg. Tuberculosis)
B.
Obligate anaerobes
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Killed by oxygen (eg. Clostridium tetani
in deep wounds)
C.
Facultative anaerobes
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Can use oxygen if it is available (eg. E.
coli in human intestines)
Reproduction
1. Binary Fission (asexual reproduction)
• Method of reproduction for most bacteria
• Occurs under normal conditions
• Process:
1. DNA replicates (ie. doubles)
2. Cell divides
3. Result: 2 identical daughter cells
2. Conjugation (sexual reproduction)
• DNA is exchanged between bacteria cells
• Cell to cell contact using pili
• Increases diversity
3. Transduction (sexual)
• Use of viruses to transfer DNA between bacteria cells
• Video clip
4. Transformation (sexual)
• Bacteria cells that pick up DNA from dead bacteria
cells
Video clip
Endospores
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Some bacteria can transform into dormant
state called an Endospore
A way to survive difficult conditions
Involves the formation of a thick wall around
itself
They are able to resist:
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heat
drought
radiation
Diversity of Bacteria
1. 2 separate Kingdoms
2. Method of Obtaining Energy
3. Environment where they live
4. Cell Wall
• Gram Positive or Negative
5. Shape (circle, rod, spiral)
6. Cellular Respiration
7. Colony Appearance
• Colour
• Shape (paired, clumps, chains)
• Shininess
Practical uses for Bacteria
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Bacteria is both beneficial and essential for humans
• E. coli, which is present in the colon, metabolizes
fecal material and allows animals to absorb the
minerals and Vitamin K that is produced.
• Used in food production (cheese, yogurt)
• Decomposers(recycling of nutrients, supplying O2)
• Nitrogen fixing bacteria in plants(used for growth)
• Antibiotic production
Practical Uses for Bacteria
Bacteria are also used in the process of producing
recombinant DNA
• DNA from another source is placed into the bacterial
DNA
• This creating a new useful strain
• Utilizes bacteria to mass-produce proteins of specific
interest like:
• blood clotting factor
• hormones
• insulin