Solution The Faster The Bead example essay topic

Biology Coursework Alginate beads experiment Aim: To investigate the effects of substrate concentration on an enzyme reaction. Background: An enzyme is a protein formed in living cells and assisting chemical processes. Catalyst is a substance that speeds up reactions. The alginate beads are made of alginate and potato juice. The alginate bead experiment works because of oxygen bubbles which stick to the bead which makes the bead rise soon after dropping it into hydrogen peroxide. Hydrogen peroxide broken down by catalyse substrate the quicker the reaction which means more gas so more rise, this can be seen in the my graph as the concentration.

The more concentrated the catalyse solution the quicker the bead rises. Collision theory: The key factors which affect the rate of a chemical enzyme are the concentration, temperature and surface area. The greater the surface area the more bubble caused by the reaction it will take for the bead to rise. Ph also affects the rate of an enzyme reaction. The rate of reaction speeds up the higher the concentration same with an increase in temperature will speed up reactions because heat will increase the speed as it will cause atoms to move faster and more. Prediction: I believe the more concentrated the solution the faster the bead will rise.

This is because of the oxygen bubbles. Starting slow with a low concentration and getting fast with an increasing concentration. Fair test: I will make sure all the concentrations are as accurate as I can get them, I will drop the beads from a set height each time the temperature will affect it but I cant do any thing about this unless I was in a temp controlled room or I could use a water bath, and with surface area I will choose 5 beads of around the same size. I will also complete my experiment in the same day to make sure none of the beads go off. Method: Apparatus: A beaker, clean pipettes, a sieve, a measuring cylinder and a stop clock. - To make the beads you mix some potato juice with some sodium alginate paste in a beaker.

- Add drops of the mixture into calcium chloride solution to make sure there even sizes. - Wash the beads (coated with catalyse) in a sieve. - Select beads of similar size to test. To make the dilutions of catalyse you work out to what percent you want to test with the dilute it until it is at the right solution percentage. To test the dilutions with the beads take one bead and drop it into a mild solution do this a few times so you know what to expect.

The dilutions I have chosen are 5, 10, 15, 20%. I choose these dilutions because there within range of diluting and its all goes up in 5 so it easier than doing any old percentage. This is the formula I have used is: Where C 2 = the concentration of the diluted solution. C 1 = the concentration of the stock solution. V 2 = the volume of the diluted solution to be made. My graph has a very steep shape to it.

The concentration dilution changes the time taken for the reaction to take place quite noticeably. I think my set of results is a good and reliable source of information and could be used in proving my prediction. Evaluation: I think my results are reliable and yes my averages do lie on my line of best fit. No my results are not close together.

I do have an anomalous result on my graph and a probable cause of this is air already trapped inside the bead or the density of the bead could be very different from the rest. To of prevented this I could of weighed them. The reliability of my results is to my knowledge as accurate as I can get them as I repeated my experiment 3 times and they have given me an average, especially the dilutions which took most time preparing. The accuracy of my results isn't one hundred percent as I could have been a bit quick or slow with the stop clock. To improve my practical I could use a different range of concentrations and clean every single bit of the equipment I use though roly before using it. Out of all the key factors there wasn't one that I couldn't control apart from temperature as it is impossible to keep the room temp the same in a normal classroom.

I could use a water bath though this could keep the temp the same. To increase the fairness of this experiment I could set all the alginate beads off at the same time. I can be positive that the effects I have seen apply to other enzymes / catalyse when speeding up the time or reaction.