Concept 27.1: Structural, functional, and genetic adaptations contribute to prokaryotic success Most prokaryotes are unicellular, although some species form colonies Prokaryotic cells have a variety of shapes The three most common of which are spheres (cocci), rods (bacilli), and spirals
Metabolic Relationships to Oxygen Prokaryotic metabolism varies with respect to oxygen: – Obligate aerobes require oxygen – Facultative anaerobes can survive with or without oxygen – Obligate anaerobes are poisoned by oxygen
Antibiotics and bacteria Penicillin. Prevents Gram- positive bacteria from forming peptidoglycan, the major component of the cell wall. Without peptidoglycan, internal pressures cause the bacterium to swell and burst. Tetracycline antibiotics. Broadspectrum drugs that inhibit the growth of Gram- negative bacteria, rickettsiae, chlamydiae, and certain Gram-positive bacteria.