Factors affecting enzyme activity

Enzymes are sophisticated catalysts for biological processes. These practicals (and the practicals at intermediate level) give you opportunities to explore how enzyme activity changes in different conditions.

Enzyme experiments often provide real ‘messy’ data, because their activity can change dramatically from one lesson to the next.

Experiments

• Microscale investigations of catalase activity in plant extracts
  Adsorb microscale quantities of plant extract onto filter paper discs and assess catalase activity by comparing times taken for the discs to surface in hydrogen peroxide solution.
• Investigating an enzyme-controlled reaction: catalase and hydrogen peroxide concentration
  Use catalase in pureed potato and investigate the effect of changing hydrogen peroxide concentration on rate of production of oxygen.
• Investigating effect of temperature on the activity of lipase
  A simple protocol that measures the effect of changing temperature on the time taken for lipase to break down the fat in milk to form fatty acids (and glycerol).
• Investigating the effect of pH on amylase activity
  Measure the time taken for amylase to completely break down a sample of starch, using buffers for different pHs.
• Investigating effect of concentration on the activity of trypsin
  Measure the time taken for different concentrations of trypsin to digest the gelatine coating on exposed photographic film and release the blackened silver halides.