Download Capsule – a thick, gel-like, protective coating on some bacteria cells

Since bacteria
have no true
nucleus or
organelles
surrounded by a
membrane, this
makes them
prokaryotic cells.
There are two kingdoms
of bacteria:
Kingdom Archaebacteria – live
in extreme environments (salt
lakes, volcanoes, ocean vents)
Kingdom Eubacteria –
these are common
bacteria and are often
called germs.
Parts of a bacteria cell:
Cell wall –
gives bacteria
their shape.
Cell membrane – regulates what goes
in and out of the cell.
Cytoplasm – water-like substance that
fills the cell and aids in storage.
Parts of a bacteria cell:
DNA - a single,
circular
chromosome
located in
the cytoplasm.
Remember, bacteria cells do not
have a nucleus.
Parts of a bacteria cell:
Capsule –
a thick, gel-like,
protective
coating on some
bacteria cells.
Pili - short, hair-like protein
structures on the surface of some
bacteria that help them stick to host
cells.
Parts of a bacteria cell:
Flagella long protein
structures
that turn to
propel some
bacteria cells.
Capsule - a thick, gel-like, protective
coating on some bacteria cells.
Shape:
Grouping:
Respiration:
Gram Stain Characteristics:
Cocci - round
bacterial cells.
Bacilli - rod-shaped
bacterial cells.
Spirilli - spiralshaped bacterial
cells.
diplo - a prefix used
with the shape name to
indicate pairing of cells.
strepto - a prefix used
with the shape name to
indicate filaments.
staphylo - a prefix used
with the shape name to
indicate clusters.
Obligate anaerobes - cannot
survive in the presence of
atmospheric oxygen.
Facultative anaerobes can live with or without
atmospheric oxygen.
Obligate aerobes - cannot
survive without atmospheric
oxygen
Gram-positive bacteria have a thick
peptide layer, retain the crystal violet,
and appear purple when viewed under a
microscope.
Gram-negative bacteria have a thin
peptide layer, take up the pink stain,
and appear pink when viewed under a
microscope.
Many antibiotics have no effect on
gram-negative bacteria.
Most are heterotrophic
because they use food
produced by other organisms.
Bacteria are often
called decomposers
because they feed on
dead or decaying
organic matter.
Some are autotrophic - able to
produce their own food.
Photoautotrophs - use
sunlight as a source of
energy like plants.
Chemoautotrophs - use
energy from chemical
reactions to make their
food.
Asexual, by binary fission - the
DNA replicates and then the cell
pinches inward and splits in two.
Conjugation - two cells
exchange a portion of their
DNA across a bridge
formed between the cells.
Following this exchange, the
cell goes through binary
fission.
While this increases the genetic
variability in the organisms, it is
not true sexual reproduction.
Endospores - during
adverse conditions,
the DNA is encased in a
protective envelope. This
endospore can lie dormant (like a
seed) for years or until
favorable conditions return.
Happens only in gram+ bacillus
Trillions of “good”
bacteria live in
your body –
mostly in your
intestines.
Lactobacillus
acidophilus
It protects the intestines, aids
in digestion, builds immunity
to food allergies, and lowers
cholesterol.
Bacteria is also
useful in making
many of our
foods.
Examples: Swiss cheese, yogurt,
vinegar (used in making pickles),
sauerkraut
Bacteria are also useful
in making medicines and
antibiotics that destroy
other types of bacteria.
Antibiotics are
chemicals that
inhibit the growth
of some bacteria.
Two common antibiotics are:
Penicillin is an antibiotic that
interferes with cell wall synthesis.
Tetracycline is an antibiotic that
interferes with bacterial protein
synthesis.
Many antibiotics
are derived from
chemicals that
bacteria and
fungi produce.
The over-use of antibiotics
through the years has lead
to some bacteria that are
almost immune to
treatment with them.
Bacteria play an
important role in
our environment:
Bacteria are important to the
Nitrogen Cycle.
Bacteria change nitrates,
nitrites and ammonia into a
usable form of Nitrogen.
Bacteria play an
important role in
our environment:
Bacteria are decomposersnatures recyclers!
Bacteria cause many
diseases in animals and
plants.
Bacteria can enter the body
through openings such as the
mouth, nose, and eyes….. Also
any open wound.
Botulism (Bacillus botulinum )
creates a toxin that is found
in inadequately prepared
food.
Salmonella causes vomiting,
diarrhea, and fever. Prevented
by fully cooking eggs and
poultry, washing hands and
cleaning kitchen surfaces often.
Strep Throat (Streptococcal bacteria) is
caused by a bacteria.
Symptoms: fever, severe sore throat,
swollen glands.
Necrotizing Fasciitis is caused by a
bacteria.
This is a rare flesh eating disease that
enters through openings in the skin.
How can bacteria be transmitted?
Animal or Human
Carriers
Food that is
uncooked or not
fully cooked
Indirect contact
Insect Carriers
Contaminated
Water or Food
Direct contact
Contaminated
Soil
Airborne