BIOL 1202 Chapter : Chapter 27 Prokaryotes
Document Summary
Concept 27. 1: structural and functional adaptations contributed to prokaryotic success. Range in size from 1 microliter- 5 microliters. Prokaryotic cells have a variety of shapes the three most common are spheres (cocci), rods (bacilli), and spirals(spirilli) Maintains cell shape, provides physical protection, prevents cells from bursting in a hypotonic environment. May also have an outer phospholipid membrane. A capsule (a sticky layer of polysaccharide or protein) may cover the cell wall of prokaryotes. Fimbriae and pilli allow prokaryotes to stick to their substrate or other individuals in a colony. Motile bacteria move by means of flagellae. In a heterogeneous environment bacteria exhibit taxus (ability to move toward or away from certain stimuli) Prokaryotes do not have membrane- bound organelles. Some do have specialized membranes that perform metabolic functions. Prokaryotic chromosome (circular dna found in the nucleoid region) Additionaly genes not always necessary for basic survival. Concept 27. 2: rapid reproduction, mutation, and genetic recombination promote genetic diversity in prokaryotes.
