BIOL1020 Study Guide - Lac Operon, Catabolite Activator Protein, Lactose Permease
Document Summary
Able to adapt to any environment i. e. acidic, salty, cold, hot. Most are unicellular but some form colonies. Most cells are 0. 5-5 m (20x smaller than eukaryotic cells) Mostly spheres (cocci), rods (bacilli) or spirals. Cell wall maintains cell shape, provides protection and prevents cell from bursting in a hypotonic environment. Bacterial cell walls contain peptidoglycan, a network of sugar polymers cross-linked by polypeptides. Gram stain: classification into gram-positive and gram-negative based on cell wall. Gram-negative have less peptidoglycan, an outer membrane that can be toxic and are more likely to be antibiotic resistant. 10x more bacteria than cells in human. Nitrogen fixing rhizobia in legumes (uptake nitrogen from soil) Antibiotics target peptidoglycan and damage bacterial cell walls. Do not target human cells due to lack of peptidoglycan. Substance from contaminating fungus prevented staphylococcal growth. Used to treat infectious disease i. e. wwii. Resistance to penicillin reported in some pathogens soon after its introduction.
