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Does changing the concentration of enzymes affect the rate of an enzyme- controlled reaction?

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Jo Foster Does changing the concentration of enzymes affect the rate of an enzyme- controlled reaction? Enzymes are biological Catalyst; catalysts are substances that increase the rate of chemical reactions without being used up. Enzymes remain unchanged throughout a reaction, unless denatured usually above 45ºC. Enzymes are also proteins that are folded into complex shapes that allow smaller molecules to fit into them. The place where these substrate molecules fit is called the active site; this is the ‘lock and key mechanism’. Enzymes remain unchanged throughout a reaction, a catalyze can be used over and over again, it does not get used up. Enzymes create a reaction by using some thing called the ‘lock and key’ method. Without enzymes we would cease to exist. If we did not have them when our body is at body temperature: 37ËC the chemical reactions would be slow to keep us alive. One way of speeding up a reaction is to increase the temperature. As the temperature rise molecules: 1. Have more energy. 2. Move around faster and collide more often. 3. React more easily when they collide. A higher body temperature could speed up the chemical reactions in your body. Bu higher temperatures damages human cells. ...read more.


I weigh all of my cubes on a balance and they all weigh 1.50g precisely. Before I start for health and safety reasons I put my safety goggles on. I set up my clamp stand and burette then I poured my hydrogen peroxide in to the burette, measuring out 20mL. I then prepare my equipment by filling my bowl up with water; I then place my measuring cylinder vertically in the bowl full of water ensuring it is full. I then stick the end of the delivery tube into my measuring cylinder, this way I can see clearly how much gas is produced and I face the measurements along the side of the measuring cylinder facing me. I will make my experiment accurate by instead of counting the bubbles I will time how long it takes to collect 20cm3 of oxygen. I am measuring the volume of gas produced this time instead of counting the bubbles because in my previous experiment I counted the amount of bubbles produced in the time space of three minuets, this did not prove accurate or very reliable as the size of the bubbles are variable. I then decided measuring the volume of gas produced would prove a fairer, more accurate test with much more reliable results. ...read more.


The more enzymes there are the more reactions there will be between the ?active site? and the ?substrate? causing oxygen to be produced. Evaluation: All of my error bars are very small, suggesting my results are reliable and accurate, all aside from my recording with one potato cube; the error bar is slightly bigger than the others. Obviously in my experiment there will be things that went wrong that couldn?t be helped such as it can be difficult to read the measuring cylinder precisely. The results I got matched my prediction which was that the reaction will produce 20ml of gas quicker when the concentration of enzymes in higher. I did my experiment four times for reliability purposes and so I could see the consistency in my results. I am confident in saying my data is reliable, I believe this because I have very few outliers, my error bars are very small and I know my data is reliable because the pattern shown in my graph is consistent. The equipment I used was all fairly precise and I was careful in my measurements. I had one outlier in my results this may again be put down to reasons that can?t be helped or may be a mistake on my part in measuring the amount of hydrogen peroxide inaccurately. ...read more.

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