Pilus

Chapter 27- Bacteria and Archaea Prokaryotes live everywhere and are microscopic Concept 27.1: Structural and functional adaptations contribute to prokaryotic success Earth's first organisms were likely prokaryotes Most unicellular, although some form colonies Between .5-5 micrometers, much smaller than eukaryotic cells(10-100 micrometers) Many shapes Spheres (cocci) Rods (bacilli) Spirals Figure 27.2 Prokaryotic cell has a cell wall, which maintains cell shape, protects the cell, and prevents it from bursting in a hypotonic environment (Eukaryotes have a cell wall made of cellulose or chitin) Capsule- polysaccharide or protein layer that covers prokaryotes