BIOLOGY 242 Midterm: Lab 17
1 Nov 2016
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Document Summary
Essential nutrients: minerals, growth factors, and sources of carbon, nitrogen, and energy. Fastidious: the more growth factors that an organism requires, the more fastidious it is. Complex medium: unknown proportions and quantities of all components. Defined medium: composed of pure chemicals used in known concentrations. General purpose media: useful for growing many organisms or maintaining organisms in a lab: nutrient agar (na) and trypticase soy agar (tsa) are general purpose media used for bacteria. Selective media: contains at least one ingredient that inhibits growth of unwanted organisms without preventing growth of the desired type: selective agents: ingredients that make selective media, selective. Streak plate- negative: on the surface only. Positive: easier to perform, quicker, for isolation and distinct separate colonies. Pour plate- negative: growth of subsurface is restricted. Selective: promotes the growth of one type of organism by inhibiting the growth of others. Differential: different color based on lactose fermentation. Lactic acid will decrease the ph from lactose fermentation.
