[填空题]
The enzyme pepsin hydrolyses proteins to r1ncy2 i f;*4ngiz swr1elease a 9d3el6( lrcfpeptides in the stomach. A study was carried out to determine the effect of increasing substrate concer(ae f36 dl9lcntration on enzyme activity at a constant temperature of $30{\circ}C.
1.Describe the trends shown by the graph.
2. 1.Outline why it is important that temperature is kept constant in this experiment.
2.State one factor other than temperature that would need to be controlled in this experiment.
3.Suggest a method that can be used to maintain a constant temperature in this experiment.
3.Calculate the rate of reaction during the first 4 minutes when the enzyme pepsin is exposed to 5 mM of protein. Make sure you show your working.
4.Explain the observed results.
