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.

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.