MODULE 4 - MODULE 4 4a) Laboratory Culture of...

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Unformatted text preview: MODULE 4 4a) Laboratory Culture of Microorganisms What does a cell need to grow? Catabolism: must be able to take up energy from chemicals or light o Energy is used for motility, nutrient transport, etc. o Energy for biosynthesis of macromolecules that make up physical nature of cell o Transformation of chemicals results in waste products excreted from cell Waste products may be nutrients for other types of cells Anabolism: nutrients taken in by cell, used for biosynthetic processes of cell Energy classes of microorganisms Phototrophs: use light as energy source Chemotrophs: use chemicals o Chemoorgantrophs: organic chemicals o Chemolithotrophs: inorganic chemicals Culture media Two main classes: defined and complex Defined medium: made from purified chemicals for which exact nature is known o Defined culture medium for e.coli o E.coli very good at maing a the cell components that it requires for growth from these basic building blocks: phosphate, nitrogen, carbon o L. Mesenteroides cannot grow as it cannot make necessary components itself if even one amino acid, purine or vitamin is omitted Called a fastidious organism Complex: exact chemical composition is unknown o Have specific recipes but may contain components of unknown composition Are only required nutrients provided in a defined growth medium? In complex, often much more than required nutrients are provided Defined media may sometimes contain more than required nutrients depending n reasons for growth of organism o Although many organisms can produce vitamin biotin, often prefer to take in existing biotin from environment o Although biotin isnt strictly reuqried for growth, medim is sitll defined growth medium since the composition of the medium is known Aseptic technique Used when cultivating microorganisms or working with tissue cultures Set of guidelines and protocols used to ensure no contamination during handling of culture Ensures person handling culture is not exposed to harmful microorganisms 4b) Cell growth Individual cell growth Some bacteria can complete one generation in 20 minutes Typically divide by binary fission, DNA replicates creating 2 copies of chromosome, cells elongate, septum forms btwn cells, one of each chromosomes attach to wall of daughter cell to ensure each is viable One generation completed after division is finished Equivalent to mitosis in eukaryotes Cell division FtsZ is one of key proteins identified experimentally Fts: filamentous temperature sensitive Original FtsZ mutants found to be filamentous at high temperatures Although cells could grow at high temp, were unable to divide creating a very...
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MODULE 4 - MODULE 4 4a) Laboratory Culture of...

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