2.6 + 2.7 - environmental and genetic control of metabolism

Cards (26)

  • Why are micro-organisms used for metabolism?
    • adaptability
    • ease of cultivation
    • speed of growth
  • What are the 4 culture conditions?
    • sterility
    • temperature
    • oxygen concentration
    • pH
  • How is sterility controlled in an industrial fermenter ?
    use of a filter
  • How is temperature controlled in an industrial fermenter?
    probes and monitored by thermostat and water jacket
  • How is oxygen concentration controlled in an industrial fermenter?
    aeration paddles
  • How is pH controlled in an industrial fermenter?
    the addition of buffers
  • What is the lag phase of microbe growth?
    enzymes are being induced to metabolise substrates
  • What is the log phase in microbe growth ?
    the most rapid growth due to plentiful nutrients
  • What is the stationary phase of microbe growth?
    production of toxic metabolites, death rate is equal to growth rate
  • What is the death phase of microbe growth?
    the toxic accumulation of metabolites
  • What is a viable cell count?
    counts only the living micro-organisms
  • What is a total cell count?
    counts both viable and dead cells
  • How is a viable cell count obtained?
    using a vital stain which picks up only dead cells
  • Define mutagenesis?
    exposure to substances that increase the chance of random change to DNA bases
  • give an example of a mutagenic agent?
    UV light, or in general, radiation
  • What is a vector?
    a DNA molecule used to carry foreign genetic information into another cell
  • Give 2 examples of vectors?
    • plasmids
    • artificial chromosomes
  • What 2 enzymes are involved in recombinant DNA technology?
    • restriction endonuclease
    • ligase
  • What is the function of restriction endonuclease?
    cuts open plasmids and specific genes out of chromosomes
  • What is the function of ligase?
    seals genes into plasmid
  • What is the function of restriction sites?
    contain target sequences of DNA where specific restriction endonucleases cut
  • What is the function of regulatory sequences?
    control gene expression
  • Function of origin of replication?
    allows self-replication of the plasmid/artificial chromosome
  • Function of selectable markers?
    ensure that only micro-organisms that have taken up the vector grow in the presence of the selective agent
  • When are complimentary sticky ends produced?
    when the same restriction endonuclease is used to cut open the plasmid and the gene from the chromosome
  • labels
    A) lag phase
    B) log phase
    C) stationary phase
    D) death phase