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How differing concentrations of enzymes (in this experiment the enzyme amylase was used) affect the rate of breakdown of its substrates (in this experiment starch was used).

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Theory Enzymes are specialized organic substances, composed of polymers of amino acids that act as catalysts to regulate the speed of the many chemical reactions involved in the metabolism of living organisms. Substrate is the substance that is acted upon by an enzyme. The enzyme amylase was used in this experiment in varying concentrations. This type of enzyme is contained in the saliva and small intestines and pancreas. Starch was the substrate used. It is a complex sugar produced by plants during photosynthesis, which can be broken down into maltose and glucose. Objective of the Experiment This experiment answers the question how differing concentrations of enzymes (in this experiment the enzyme amylase was used) affect the rate of breakdown of its substrates (in this experiment starch was used). Hypothesis Our prediction was that the higher the concentration of amylase, the faster the breakdown of starch. As enzymes catalyze chemical reactions, the higher the concentration the faster the chemical reaction. As the concentration of starch was kept constant (1%) the varying concentrations (1%, 0.8%, 0.6%, 0.4%, and 0.1%) of enzymes would always breakdown the same amount of starch thus making the experiment accurate and more comparable. ...read more.


It should be drawn around 2 seconds before it is put on the iodine. 12. The amylase and starch mixture should be dropped on the iodine every 30 seconds until the time the color of the amylase starch mixture is the same as the control drop diluted with water. 13. The time should be recorded and the experiment repeated every 15 or 10 seconds rather than every 30 seconds with the same concentration of amylase. 14. Then the concentration of amylase should be changed and experiment repeated and time recorded every 30 seconds. 15. Then using the same concentration the experiment should be performed again and time recorded every 15 seconds. 16. This pattern should be followed until 0.1% concentration of amylase is reached. Data Table 1 Concentration of amylase Time taken for the starch to be broken down (recorded every 15 seconds) Time taken for the starch to be broken down (recorded every 30 seconds) 1% 60 seconds 60 seconds 0.8% 150 seconds 150 seconds 0.6% 210 seconds 210 seconds 0.4% 270 seconds 270 seconds 0.1% More than 960 seconds More than 960 seconds Data Analysis With each concentration of amylase the experiment was carried out twice (every 30 and 15 seconds intervals). ...read more.


Therefore majority of the inaccuracies were due to unavoidable human errors. Conclusion The aim of this experiment was to examine the effects of increasing concentrations of amylase on the rate of breakdown of starch. After performing the experiment we can therefore conclude that as the concentration of amylase decreases, the time taken for the starch to be broken down increases while the rate of breakdown of the starch decreases (attached graphical representation at the end of the report). Evaluation The procedure used was quite effective. We were able to come up with reasonable results although they weren't 100% accurate. The errors that were committed were mostly due to human limitations. These errors can only be rectified if performed by a machine. But there were some errors, which could have been avoided like the use of water bath, as it would keep the temperature constant. On the whole the experiment was pretty successful. Improving the Investigation As most of the errors were unavoidable human errors, it is very difficult to suggest ways of improvement. As mentioned earlier these errors are bound to happen if the experiment is performed manually. These errors can be reduced by the use of appropriate laboratory equipment. But to make the experiment more effective we should have used the water bath. 1 ...read more.

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