BacteriaArchaebacteria and Eubacteria

I. Characteristics: A. have a cell membrane. B. have a cell wall. C. prokaryotic (no nucleus/organelles.)

D. Live in damp, watery places. E. reproduce by asexual fission.

II. 2 Groups of Bacteria:

A. Archaebacteria•live in harsh environments.

B. Eubacteria•found everywhere.

III. 3 Types of Archaebacteria A. Methanogens

• live in oxygen-free environments (cow stomachs, swamps and sewage plants).

•produce methane gas.

B. Halophiles

Live in highly concentrated bodies of salt water.

•The Dead Sea

C. ThermophilesFound in hot, acidic water.

•Hot, deep-sea, thermal vents.

•Hot springs.

IV. 3 Groups of EubacteriaA. Heterotrophs

• found everywhere.

•Some are parasites.•Some are saprobes saprobes that feed on dead organisms and wastes. Ex. Recycling

B. Photosynthetic Autotrophs

Get energy from light. Have photosynthetic pigments. Some are blue-green; some

are red or yellow. In ponds and streams.

C. Chemosynthetic Autotrophs

Get energy from the breakdown of inorganic substances as sulfur and nitrogen compounds.

V. Structure of Bacteria A. Classified by the

shapes of their cells.

•1. coccus- round•streptococcus

–causes tooth decay

Staphylococcus

2. spirillum- •spiral-shaped.

•Causes syphilis.

Syphilis Bacterium

3. bacillus- •rod-shaped.

•Causes food poisoning.

Pseudomonas rods

B. Classified according to their arrangement.•1. Diplo- being paired.

•2. staphylo- grape-like clusters.

•3. strepto- long chains.

C. Overall Structure: 1. Sticky capsule-

• surrounds the cell wall for protection against the immune system of the organism.•Sticks to teeth, the host, etc.

2. Cell Wall and Cell Membrane

Outer boundaries.

3. DNA No nucleus to hold the

DNA. Arranged as 1 chromosome

in the cytoplasm.

Some have these parts:4. Endospore-

•a tough envelope that surrounds and protects the DNA in bad conditions.

5. Flagella-•used for movement.

D. Reproduction Do not reproduce by mitosis or

meiosis because there is NO nucleus.

Reproduce asexually by binary fission (cell divides into two new cells).

Reproduce sexually by conjugation conjugation (one bacteria transfers chromosomes to another through a membrane extension).

Very rapid reproduction (every 20 min.).

VI. Diversity of Bacteria

A. aerobes- most bacteria that require oxygen for cellular respiration.

•E. coli

B. anaerobes- do not use oxygen.

•Syphilis

VII. Diseases

1/2 of all diseases are caused by bacteria and their toxins.

Antibiotics are chemicals that inhibit the growth of bacteria.

Botulism is caused by improper sterilized canned foods.

Tetanus causes “lock-jaw.” E. coli causes food

poisoning.

E. coli

VIII. Economic Importance A. used to make foods as yogurt,

cheese and pickles. B.used in medicines (antibiotics). C. recycle nutrients in ecosystems.

D. change nitrogen in air into a usable form for plants.