Enzymes

• What an advantage of trapping enzymes within the gel beads?

  they can be reused
• Describe one similarity and difference between the lock and key model and the induced fit model:

  similarity - the active sites bind to the substrate forming an enzyme substrate complex which releases products

  difference - active site in the lock and key model is rigid whereas in the induced fit it is flexible

  the active site isn’t complementary to the substrate in the induced fit like it is in the lock and key
• When bread becomes stale, the structure of some of the starch is changed. This changed starch is called retrograded starch. Scientists have suggested retrograded starch is a competitive inhibitor of amylase in the small intestine. Suggest how eating stale bread could reduce weight gain:

  Retrograded starch would bind to amylases active site preventing starch from binding. This means less starch is hydrolysed by amylase into maltose so less glucose is absorbed into the blood stream via the small intestine, reducing weight gain