Here are some links to enzyme animations that will help you to understand enzymes and how they work....
http://www.sumanasinc.com/webcontent/animations/content/enzymes/enzymes.html

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html

http://bcs.whfreeman.com/thelifewire/content/chp06/0602001.html

http://www.northland.cc.mn.us/biology/biology1111/animations/enzyme.swf