1. ARCHAEBACTERIA Live in harsh conditions 2. EUBACTERIA More normal and common bacteria Archaebacteria are prokaryotes. Prokaryotes are: single celled without a nucleus organisms and are the smallest and simplest forms of life. Archaebacteria are found in anaerobic and extreme conditions (high salt, high temperature, and/or very acidic.) These are believed to be the conditions on the early Earth. Earth’s early atmosphere did not contain oxygen, therefore the earliest organisms were anaerobic. Anaerobic can live in the absence of oxygen Lives in extremely salty places. Picture on the right shows a salty pond in the Arabian desert that has turned red due to the presence of Halobacterium salinarum Thermus thermophilus is an archaean which can withstand very high temperatures. Often lives in hot springs like those found at Yellowstone. Eubacteria are also prokaryotes. Eubacteria is made up of more traditional bacteria and is a larger kingdom than archaebacteria. They are found in almost all habitats. Eubacteria are unicellular and have no membrane-bound organelles. ie: no nucleus, mitochondria, chloroplasts, ER, or Golgi apparatus. Archaebacteria and Eubacteria 1. 2. 3. Cocci spherical Bacilli rod shaped Spirilla spiral shaped Cilia and Flagella allow a bacterium to move. Cilia are hair-like and work like oars in a boat. Repetitive beating allows the cell to move. If a bacteria cannot move cilia can also move water across the cell’s surface. Flagella are whip-like and wave back and forth to move the cell. Most bacteria are heterotrophs. Heterotrophs feed on other organisms. These include parasites which live and feed off of a living host and decomposers that feed on dead and decaying organisms Some bacteria are autotrophs. Autotrophs use chemicals or photosynthesis as a form of energy. Bacteria reproduce either asexually or sexually. Asexual Reproduction Prokaryotes reproduce by splitting in two in a process called binary fission. The DNA is copied and the cell divides into two identical cells. Sexual Reproduction Combines genes from two different individuals. Prokaryotes that do not technically reproduce sexually can still mix genes with one another. 1. 2. 3. Cells that do not reproduce sexually can still mix genes through three processes: Conjugation- Two cells briefly join and one cell donates DNA to the other. Transformation – Bacteria pick up pieces of DNA from the environment. Transduction- viruses can transfer pieces of DNA from one cell to another These processes add genetic diversity to bacteria. Mutation is also a large source of genetic diversity in bacteria. 1. 2. Bacteria cause disease in two ways: By damaging tissues and breaking down cells for food By releasing toxins that interfere with the normal bodily functions of the host. 1. To treat diseases caused by bacteria we use: Vaccines small doses of live bacteria, killed bacteria, or parts of bacterial cells which cause an immune response. 2. Vaccines allow your body to learn how to kill a bacteria without getting sick. Antibiotics drugs that interfere with the growth of bacteria