MCB 2000 Chapter Notes - Chapter 4: Sulfur, Chromosome, Phagocytosis
Document Summary
Prokaryotic cells - bacteria: genetic material not enclosed with a membrane, absence of other membrane-enclosed organelles, cell division by binary fission, small; <1. 0-3. 0 m in diameter. External structures: glycocalyx capsule or slime, flagella, fimbriae and pili. Internal structures: cytoplasm, nucleoid, ribosomes, inclusion granules. Flagella: long, whip-like structures that extend beyond surface of cell, responsible for movement, present in some bacteria. Structure of flagella: basal body - anchors the flagellum to the cell wall and plasma membrane, hook anchors the flagellum to the basal body, filament - outermost region of the flagellum, composed of the protein flagellin. In gram positive bacteria: 1 pair of rings, only inner pair is present. In gram negative bacteria: 2 pairs of rings, outer pair of rings is attached to the cell wall, inner pair anchored to the plasma membrane. Motility of bacteria enables them to move towards or away from the environmental stimuli - taxis.
