进行酶活力测定时应如何控制底物浓度和酶浓度

一般酶量要少，底物要过量。这样比较容易测到初速度。
具体要看你的反应和测活方法。

你到底想测什么?
酶的活性与底物有关的吗?与酶浓度有关吗?调节酶和底物浓度的实验只能反映催化效率!
想测酶活性应将酶和底物浓度设定值,温度为变值.因为影响酶活性的是温度,与其他无关!
噢no!答完你这问题就耽搁了我睡觉了,我还在高3啊!明天怎么办!又打瞌睡了~-~

You will need to make a standard curve at the beginning by a standard enzyme from company like sigma, or by the decrease of substrate or increase of product.
The concentration of substrate should be set to maximum, which together with temperature and reaction time so on and so on, need to be set before your final experiment

If you never did this experiment, it is better off to find someone else to help you