Daily Archives: May 2, 2009

Enzymes – catalysts of digestion!

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These pitcher plants and other ‘carnivorous’ plants produce digestive enzymes that can break down the flesh of small invertebrates, such as flies, spiders and ants. Often they grow in soil that is deficient in specific inorganic nutrients, such as nitrates and phosphoros, and can get these essential elements from the dead animals that are attracted by sweet and sticky liquids.

The main things to remember about enzymes are:

  1. Enzymes are proteins and biological catalysts.
  2. They are not used up in the reaction – only a small amount of enzyme is needed for each reaction.
  3. They do not change the amount of product formed
  4. They speed up a reaction, but do not change the direction of the reaction.
  5. They are very specific to their substrate and are often named according to the chemicals they work on.
  6. Enzymes, being proteins, are sensitive to heat, pH and heavy metal ions. When heat is applied the proteins are ‘denatured’ and no longer work. 

In the human body there are several different enzymes including:

  • Amylase which works on starch
  • Maltase which works on maltose
  • Sucrase which works on sucrose
  • Lipasewhich works on lipids (Fats) and
  • Pepsin which works on polypeptides (Proteins)

More about Enzymes from Wikipedia here. Award-winning Enzyme Investigation here. Andrew Douch, a Biology teacher from Wanganui Secondary College, has produced many Biology podcasts, for students to learn about different topics – here is a link to his “Enzymatic” podcast. Andrew has also included some notes about enzymes here. Experiment with enzymes in liver here.