In chemical reactions involving enzymes, the substrate proteins are huge molecules that will only react with each other if they're aligned just the right way. If they are permitted to interact with the enzymes present, the won't collide and react often enough for the reaction to do any good.The enzymes align the molecules, basically acting like "molecule shepherds," showing them the way they need to react.This speeds up the reaction greatly, making things like digestion possible. Hope this is helpful
