Topic 3.6 Enzymes

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Topic 3.6 Enzymes
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Define enzyme and active site

• Enzyme protein catalysts that speed up the rate
  of chemical reactions
• Active Site - part of an enzyme where substrates
  bind and undergo a chemical reaction

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EXPLAIN the effects of temperature, pH and
substrate concentration on enzyme activity
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Define denaturation

• a process in which proteins or nucleic acids
  lose the tertiary structure and secondary
  structure which is present in their normal state,
  by application of some external stress or
  compound such as a strong acid or base, a
  concentrated inorganic salt, or heat.
• Loss of structure loss of function

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Introducing Enzymes

• They are catalysts so the make reactions
  easierThis increases productivity and yield
• Globular proteins
• As catalysts they are not consumed by the
  reactionThe may be used over and over again
• Enzymes show specificity to the reaction they
  control
• Enzymes are sensitive to their environment so
  they can be controlled by adjusting the
  temperature, the pH or the substrate
  concentration

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Enzyme-Substrate Specificity
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Enzymes have been used in biotechnology for
millennia
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Lactase

• Lactase is used to remove the sugar lactose from
  milk and other dairy products

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Lactose intolerance

• Some people are intolerant of lactose in milk
  they cannot digest it
• The lactose remains in the digestive system and
  is fermented by bacteria
• The result is nausea, cramps, bloating, gas, and
  diarrhea occurring within 4h of consuming milk
  products
• The treatment includes taking a tablet of lactase
  enzyme with a meal
• The lactase digests the lactose in the food
• A special lactose free diet may be necessary

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Source

• Lactase enzyme (?-galactosidase) is extracted
  from fungi such as Aspergillus oryzae

http//www.biologie.uni-regensburg.de/
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Reaction

• Substrate Lactose

This is a hydrolysis reaction
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Advantages

• Lactose intolerant patients can digest their food
• Lactose free products can be prepared for special
  diets
• Lactase is used to hydrolyse lactose in ice cream
  into glucose and galactose to give it a sweeter
  flavour

Stoney Creek Dairy