Aim: I am going to investigate how different surface areas, and therefore enzyme concentration, of the same volume of potato affects rate of reaction, when placed in 10ml hydrogen peroxide. Prediction: As the surface area increases, so do the amount of enzymes, which are biological catalysts that are on show, free for the hydrogen peroxide to collide with. Because the catalase and hydrogen peroxide are a complimentary pair, and the enzymes are the ones that break down the substrate, then the more enzymes there are, the more hydrogen peroxide will be reacting at once, and once that...
not used up, or does not differ after the reaction; it can be used again and again after countless reactions. It also does not cause the reaction, but simply speeds the reaction up.

I also kept the same potato, for each set of results I took three, as using lots of different ones could have produced unreliable results, as different potatoes' enzymes' reaction times may differ slightly. I did 5 different experiments each on 3 different potatoes 5 experiments on each, to obtain accurate results incase one potatoes enzymes were very different from most.