Bacteria

General Characteristics Prokaryotic: single-celled organisms that lack nuclei & about 1-5 microns in size Move about using cilia or flagella

3 Basic shapes Bacilli (rod shaped) Spirilla (spiral shaped) Cocci (round shaped)

Autotrophic: either photoautotrophic or chemoautotrophic Heterotrophic: aerobic, anaerobic, or facultative anaerobic (live with or w/o oxygen)

Reproduction Asexual reproduction: binary fission, replication of DNA then divides in half. Sexual reproduction: conjugation, where they swap DNA In unfavorable conditions, Endospores are formed where DNA is enclosed in a protective “shell”. Bacteria Clock

Bacteria in Nature Decomposers: break down dead & decaying matter. Recycles nutrients into the environment. Fix nitrogen for soil Purifies water Produces CO 2 for animals and plants

Bacteria & Desease Few actually cause disease. They are called Pathogens: disease causing agents Two ways bacteria cause disease: damage & toxins –Heterotrophic bacteria damage cells and tissues –Metabolic waste can be a toxin and travels throughout the body and poisons you. See Botulism in the book.

Controlling Bacteria Antibiotics: blocks the growth & reproduction of bacteria Sterilization by heat or chemicals kill most bacteria. Archaebacteria are ancient bacteria and are sometimes called extremophiles. These things live in extreme thermal or chemical areas. What could control these types of bacteria?

Beneficial Bacteria Food: yogurt, cheese, sauerkraut, etc. Industry: digest petroleum products which is good for environmental cleaning efforts, and many others. Makes drugs & medicines.