Bacteria Notes

Bacteria cell

Key Terms Bacteria are prokaryotes. The genetic material in the cells is not contained in a nucleus. Discovered in the 1600s because of the use of microscopes. Most bacteria cells contain – cytoplasm, ribosomes, and use flagella to move.

Key Terms Cytoplasm – gel like substance within the cell membrane. Ribosomes – protein factories Flagellum (plural is flagella) – whip like tail on the outside of the cell that is used for transportation.

Bacteria Shapes Cocci – round like a ball Bacilli – long, rod like Coccobacillus – combination of the two – like a jellybean Vibrio – curved like a boomerang Spirillum – rigid, spiral shaped Spirochete – flexible, spiral shape like a telephone cord Pleo morphic – various shapes that do not fit the other categories Filamentous – branch like

Bacteria Names Diplobacilli – rod shaped bacteria in pairs Streptobacilli – rod shaped bacteria in chains Staphylococci – clusters of round shaped bacteria

Autotroph or Heterotroph? Some bacteria are autotrophic and make their own food. Some collect energy from the sun like plants do. Others use the energy from chemical reactions. Some bacteria are heterotrophs. They need to get their energy from another source.

Bacteria and Energy When bacteria cells break down food for energy – it is called respiration. Some bacteria need oxygen to break down the food source. They are called aerobic bacteria. Anaerobic bacteria DO NOT need oxygen.

Bacteria Sex!!!!! Some bacteria reproduce by making identical copies of themselves. This is called Asexual Reproduction or Binary Fission.

More Bacteria Sex!!! Some bacteria reproduce with a partner. This is called sexual reproduction or Conjugation. The offspring will have genetic traits from both parents. They are not identical to the parents.

Even More Bacteria Sex!!!! Sometimes – bacteria can’t reproduce due to their surroundings. To help them reproduce, they can create endospores. Endospore formation is a survival technique for bacteria during unfavorable conditions (no food or water).

So why do we care about bacteria? Oxygen production Adds O2 to the atmosphere Food production Can turn foods sour (sour cream, vinegar) Pasteurization Environmental recycling Nitrogen fixating bacteria help to break down natural matter, so it can be used again by another organism. Environmental clean up Some bacteria are used to help clean up oil and gasoline spills. Health and medicine Some bacteria help digest vitamins in the human body as well as fight off other diseases. (Think Activia!!)