BIOL 1202 Chapter : Prokaryotes
Document Summary
One things that e. coli and other bacteria have in common with eukaryotes is the presence of ribosomes. Concept 27. 1: structural and functional adaptations contribute to prokaryotic success: prokaryotes are unicellular, some colonial forms, range in size from 1-5 micrometers, thiomargarita namibiensis (750 micrometers, no membrane-bound organelles, circular chromosomes. Prokaryotic cells have a variety of shapes: the three most common are spheres (cocci), rods (bacilli), and spirals (spirilli) Cell-surface structures: cell wall, maintains cell shape, provides physical protection, prevents cell from bursting in a hypotonic environment, composed of peptidoglycan in bacteria, may also have an outer phospholipid membrane. Gram negative: a capsule (a sticky layer of polysaccharide or protien) may cover the cell wall of many prokaryotes, fimbriae and pilli allow prokaryotes to stick to their substrate or other individuals in a colony. Figure 27. 5: motile bacteria move by means of flagellae, structurally different from eukaryotic flagella.
