MIC 4124 Lecture Notes - Lecture 1: Bacterial Capsule, Horizontal Gene Transfer, Gram Staining
Document Summary
Cocci arranged in clusters or chains: diplococci with one plane of division, tetrads with 2 planes of division, sarcinae have 3 plans of division to make cubical packet of 8 cells. Irregular shape when division in any plane (cluster) Classified on thickness, twists, or flexibility: hyphae. Small bacteria: allow for high metabolic rate because of large surface to area ratio, reactions limited by diffusion but small cell. Instead of a nucleus found in eukaryotes: not membrane bound. Often single circular chromosome: usually no introns, haploid genome. General structure: capsule is polysaccharide layer. Protection from osmotic stress and from host immune system: cell wall provides protection from osmotic stress, defines shape, protects from toxic substances, may contribute to pathogenesis, cell membrane. Chemical and metabolic processes like respiration and photosynthesis, lipid metabolism. Detection of cues for chemotaxis by receptors. Nutrient and waste transport with selectively permeable barrier. Mechanical boundary of the cell and retains cytoplasm.