[填空题]
A study has been conducted on the acti1txie( l+aut6 vity of a specific lactase (Bg1i fm ;oc:.u)drxjy08:rhupnr+v9s 2uc8 ;qfy0), analysing the effect of pH, temperature and glucose concentration, as it may potentialld+cjpyruo hr2s :u0 c ix:9;n r.;qu8fyf)mv8y be used as a commercial lactase to produce lactose-free milk.
1.Deduce which temperature used in this experiment was the optimum one for the enzyme Bg10. Give a reason for your answer.
2.Explain the change in enzyme activity at temperatures above $40^{\circ}C$.
3.Evaluate whether the data supports the claim that the optimum pH for the lactase enzyme Bg10 is 7.
4.Calculate the percentage difference in relative activity of the enzyme Bg10 when treated with 500 mM of glucose compared to 50 mM of glucose. Make sure you show your working. %
Further studies have been conducted on other lactase enzymes to test their thermal stability at an optimum temperature of 60°C, when they are immobilised on graphene nanosheets, in comparison to lactase enzymes floating freely in milk.
5.Compare the trend shown by the immobilised enzyme to that of the soluble enzyme.
6.Calculate the range of data for the soluble enzyme over 10 minutes. log %
The storage stability at room temperature of the immobilised enzymes has also been compared to lactase enzymes floating freely in milk.
7.Compare and contrast the storage stability of the immobilised and free soluble enzyme.
The reusability of the immobilised enzyme was tested, by analysing the activity of the immobilised enzyme over 10 uses.
8.State one advantage of being able to reuse immobilised enzymes.
9.Using the data provided, and your own knowledge, suggest why immobilised enzymes should be used to make lactose free milk.
