BIOL 1002 Lecture : Ch19bionotes
Document Summary
Shape, locomotion,nutrient requirements,colony appearance, gram staining, dna sequences. Polysaccharide/ protein cell walls of some bacteria are sticky. Endospores -> form inside bacteria under some extreme conditions. Sex pilus connects to recipient via cytoplasmic bridge. Some bacteria can switch between aerobic and anaerobic respiration. Bacteria break down cellulose for leaf-eating animals (cattle) Nitrogen fixing bacteria convert n2 gas to water soluble nh4 and ammonium in the soil. Fixers live in specialized root nodules, found in soybeans,clover etc. Bacteria can biodegrade nearly all human made substances. Bacteria break down dead organisms and nutrients for reuse. Clostridium tetani causes tetanus, enters through puncture, produces paralyzing poison. Clostridium botulinum causes botulism, active in under sterilized food. Caused by yersinia pests; spread by rat fleas. Flu like symptoms leading to arthritis and nervous system problems. No cell membrane, no cytoplasm,no ribosomes -not living. Bacteria are infected by bacteriophages, which are viruses that specifically attack bacterial cells.
