BIOL 1202 Chapter : Chpt 27
Document Summary
Motility (fig 27. 6: motile bacteria move by means of flagellae, structurally different from eukaryotic flagella. In a heterogeneous environment bacteria exhibit taxis(ability to move toward or away from certain stimuli: e. g. positive chemotaxis- moving toward a chemical stimulus. Internal organization: prokaryotes do not have membrane-bound organelles, some do have specialized membranes that perform metabolic functions. Genomic organization: prokaryotic chromosome ( circular dna found in the nucleoid region, not within a nucleus, plasmid ( smaller circular dna rings, additional genes not always necessary for basic survival, e. g. , antibiotic resistance. Reproduction: prokaryotes reproduce quickly by binary fission, can divide every 1-3 hours, forms of asexual reproduction, produces genetically identical daughter cells. Concept 27. 3: diverse nutritional and metabolic adaptations have evolved in prokaryotes. ** major nutritional modes in prokaryotes (table 27. 1) Nitrogen metabolism: some prokaryotes can metabolize nitrogen. In nitrogen fixation, bacteria convert n2 (nitrogen gas) to nh3 (ammonia)
