biotechnology

• define biotechnology: the use of microorganisms, cells, or cell components to make a product
• what are the 3 main areas that biotechnology is used: food

  pharmaceutical drugs

  enzymes

  other
• general advantages of using microorganism in biotechnology: cheap and easy to grow

  short life cycle and grows in normal atmospheric pressure and lower temperatures
• How is yogurt made? milk is fermented converts lactose and lactic acid
• what ferments lactose into lactic acid

  lactobacillus balgaricus
• what does the high acidity cause the milk to do: denaturing it causing it to coagulate
• define coagulate


  Process that thickens or congeals a substance
• what can be added to the yogurt which can benefit human and what does it do: bacteria to improve digestion and aid gastrointestinal function
• what is milk pretreated with to make cheese: bacteria (lactobacillus)
• what is the milk mixed with once it solidified: rennet which contains rennin (chymosin)
• what does rennet do: coagulates milk protein casein in presence of calcium ions
• what is broken down which makes kappa-casein insoluble


  kappa-caesin
• what is the caesin precipitated by: the action of the calcium ions
• what is the remaining solid called

  curd
• what happens before the curd is pressed into moulds: separated from the liquid and continues producing more lactic acid
• what are the 3 key steps of bread making: mixing = dough

  proving/fermenting = dough respires anaerobically = CO2

  cooking=any alcohol evaporates
• what are alcoholic beverage the product of: anerobic respiration of yeast
• advantages of using microorganism: high protein content

  contain no animal fat or cholesterol

  can easily be GM to adjust AA

  independant of the season

  no animal warefare issues
• disadvantages of using microorganism: has to be purified to make sure it isnt contaminated

  infection

  palatability
• what conditions need to be controlled to ensure the best possible yeild of product: temperature

  nutrients

  O2 lvls

  ph

  concentraation of product
• what are primary metabolites: Products synthesised by a microorganism during normal metabolism when they are actively growing. Such products are continually released from the cells and can be extracted continuously from the fermenting broth.
• what is continuous culture: To keep microorganisms growing at a specific rate, the fermenting broth is topped with nutrients, which the microorganisms use. Some broth is also removed regularly to extract the product and remove cells; otherwise, the population becomes too dense.
• what are secondary metabolites: Products only produced when cells are placed under stress such as high population density or limited nutrient availability. These are produced mostly during the stationary phase of growth.
• the imporance of asepsis

  ensure sterile conditions are kept
• penicillin


  secondary metabolites manufactured by batch culture
• what is used to reduce the population density of microorganism: serial dilusion
• what is a closed culture: A culture which has no exchange of nutrients or gases with the external environment
• what are the 4 stages of growth of population of microorganism in a closed culture: lag phase -early growth phase

  log phase -grow and reproduce fast

  stationary phase -no population phase

  death -nutrients run out = death
• what are immobilised enzymes: Enzymes that are attached, or fixed, to each other, or to an inert material
• 4 methods of immobilising enzymes: Adsorption, covalent bonding, entrapment and membrane separation
• adsorption: The process of binding or sticking to a surface. by hydrophobic interactions and ionic links
• covalent bonds: bound to supporting surface using strong covalent bonds

  enzymes are bonded using cross-link bridges
• entrapment: enzymes are trapped in a matrix

  only suitable when product molecules are really small
• membrane separation: enzyme molecules are separated from the reaction mixture by a partially permeable membrane