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 - spiral- shaped 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 aerobes - cannot survive without atmospheric oxygen Obligate anaerobes - cannot survive in the presence of atmospheric oxygen. Facultative anaerobes - can live with or 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. Chemoautotrophs - use energy from chemical reactions to make their food. Photoautotrophs - use sunlight as a source of energy like plants.

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 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 decomposers- natures 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 () creates a toxin that is found in inadequately prepared food. 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 () is caused by a bacteria. 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 Insect Carriers Contaminated Water or Food Food that is uncooked or not fully cooked Contaminated Soil Airborne Direct contact Indirect contact