Food Production

• crop yield

  the total quantity of crop that the land produces
• eutrophication


  A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria.
• pesticide


  A chemical intended to kill pests that damage crops.
• insecticide


  a chemical used to kill insects
• herbicide


  substance that kills plants
• biological control

  the intentional release of a natural enemy to attack a pest population
• bioaccumulation


  The accumulation of a substance, such as a toxic chemical, in various tissues of a living organism.
• Fermenter


  A vessel used to grow microorganisms in large numbers.
• aseptic


  free from disease-causing microorganisms
• intraspecific competition


  competition between members of the same species
• interspecific competition


  competition between members of different species
• Agitation


  Constant moving or stirring
• Predation


  An interaction in which one organism kills another for food.
• selective breeding

  The process of selecting a few organisms with desired traits to serve as parents of the next generation
• anaerobic respiration in yeast -- glucose --> carbon dioxide + yeast
• Lactobacillus bacteria


  Bacteria that ferment lactose sugar in milk to form lactic acid
• Fermentation


  Microorganisms break sugars down to release energy (usually by anaerobic respiration)
• Industrial fermentation

  1. Microorganisms are grown in large containers called fermenters

  2. Microorganisms are grown in liquid 'culture medium'

  3. Conditions inside the fermentation vessels are kept at the optimum levels for growth
• Bacteria ferment milk to produce yoghurt
• Lactic acid

  Acid formed by lactobacillus bacteria fermenting lactose sugar in milk
• Making yoghurt

  1. Sterilise equipment

  2. Pasteurise milk

  3. Cool milk

  4. Add lactobacillus bacteria

  5. Incubate

  6. Form lactic acid

  7. Milk solidifies into yoghurt

  8. Add flavours and colours

  9. Package
• Sterilising vessels between uses

  Kills unwanted microbes
• Nutrients needed by the microorganisms for growth are provided in the liquid culture medium
• Aseptic conditions

  Increases the product yield because the microorganisms aren't competing with other organisms
• Aseptic conditions


  Means that the product doesn't get contaminated
• Water-cooled jacket

  Prevents the enzymes from getting too hot and denaturing
• Adding oxygen for respiration


  Pumping in sterile air
• Paddles that circulate the medium around the vessel

  Increases the product yield because microorganisms can always access the nutrients needed for growth