Transcript BACTERIA ARE SINGLE-CELLED ORGANISMS WITHOUT A …

BACTERIA ARE SINGLECELLED ORGANISMS
WITHOUT A NUCLEUS
• Bacteria are the simplest form of life; there are
more bacteria in your mouth than people on the
planet.
• BACTERIA & ARCHAEA are the SMALLEST
LIVING things.
• BACTERIA & ARCHAEA are found in MANY
ENVIRONMENTS
• BACTERIA MAY HELP OR HARM OTHER
ORGANISMS
BACTERIA & ARCHAEA are
the smallest living things
• Bacteria are the simplest kind of life known
(1cell with loops of genetic material-no nucleus;
reproduces via binary fission)
• Bacteria have cell walls surrounding & protecting
the soft cell membrane.
• Classify bacteria by external shape:
• SPIRAL-shaped occur in single strands
• ROD-shaped occur singly or in chains
• ROUND-shaped occur singly, in pairs, chains or
clusters.
ARCHAEA & BACTERIA IN
MANY ENVIRONMENTS
• ARCHAEA: single-celled organisms living in the
most extreme environments (hot, cold, salty, etc.)
• METHANOGENS: archaea that make methane
& die if exposed to oxygen (live in marshes &
intestines of cows & termite)
• HALOPHILES: archaea that live in salty lakes &
ponds
• THERMOPHILES: archaea that live in extreme
heat or cold. (hot springs, under water volcanic
vents, or buried deep in ice).
ARCHAEA & BACTERIA
• Some bacteria have chlorophyll & use sunlight
for energy. (important food source in oceans &
give off O2 as well)
• Many bacteria are grouped by role they play in
environment:
• PRODUCERS: transform energy from sunlight
to usable forms.
• DECOMPOSERS: break down materials in dead
or decaying organisms. (good recyclers!)
• PARASITES: organisms that live off a host and
harm that host
Helpful v. Harmful Bacteria
• Decomposers break down
material that other
organisms can use to
build up.
• Can break down & treat
sewage to clean water or
oil spills
• Can convert nitrogen gas
into usable nitrogen
compound for plants to
use in building proteins to
grow.
• Methanogen archaea also
help cows & termites
digest cellulose for food.
• Some diseases are caused
by bacteria (tuberculosis,
cholera, infant diarrhea)
• Cause symptoms by:
• Invade body, multiply &
dissolve cells
• Poison with chemicals
they made & released
• Poison with chemicals
that are part of
themselves
• VACCINES are used to
help organisms get ready
to fight bacteria they may
be exposed to in the
future.