This lab can be done in one class period and can be made to be either high level or basic level. I have used it both in my Honors Biology class and in my basic biology class. You can use paper or plastic atom kits. I think it helps kids to conceptualize what an enzyme does and it allows you to make it your own by telling the students just what detail you want. I often do labs like this where the groups have to show me they understand the material by modeling it for me. I give them a stamp when I feel they really "get it."