BACTERIA ARE SINGLE-CELLED 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.
Top Related