BIOL 2303 Lecture Notes - Lecture 15: Particle Size, Microorganism, Gram-Positive Bacteria
18 Apr 2018
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Document Summary
Environmental change is detected by a sensor protein, which then transmits information to the regulatory machinery. Two part signal transduction system: sensor kinase in the cytoplasmic membrane, response regulator in the cytoplasm. Sensor kinase auto-phosphorylates at the specific histidine residue. Phosphate is then transferred to the response regulator. Phosphorylation activates the response regulator which then binds dna, leading he positive or negative regulation. Many traits are density dependent: virulence factor production, luminescence, biofilm formation. Quorum sensing depends on one or more signal transduction mechanisms. Measured in terms of: species richness, species abundance. Habitats with a wide range of nutrients and microenvironments tends to have a higher. Species richness and moderate abundance of each species. Extreme environments tend to have lower species richness and a high abundance of a few species. Nutrients: carbon & nitrogen and other macronutrients, micronutrients, electron acceptors and donors. Conditions: temperature, ph, light, salinity, oxygen availability.
