Biology 1290B Lecture Notes - Lecture 3: Plasmid, Chromosome, Magnetite
Document Summary
There is tremendous diversity among the bacteria and archaea. The domain bacteria contains some of the most studied prokaryotes. The majority of the 25 phyla of bacteria play a positive role in nature. The domain archaea contains organisms with diverse physiologies. Euryarchaeota contain: methanogens (live in anoxic environments), extreme halophiles (salt-lovers), thermoacidophiles (grow at high temperatures with low ph). Crenarchaeota: tend to grow in hot, acidic environments such as hot springs and volcanic vents. Prokaryotes can be distinguished by their cell shape and arrangements. Variations in cell shape and cell arrangement exist. A bacillus is a prokaryotic cell with a rod shape. A spherical bacterial cell is a coccus: many cocci and some bacilli appear in groups or chains. Spiral-shaped bacteria can appear as vibrio (comma-shaped), spirilla (helical), or spirochete. An overview to bacterial and archaeal cell structure. Cell structure organizes cell function: sensing/responding to the surrounding environment compartmentation of metabolism. growth and reproduction.