Investigating the effect of enzyme activity

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Malaz 1i

Investigating the effect of enzyme activity


Almost all chemical reactions that occur in living organisms are catalyzed by enzymes. The aim of this experiment is to investigate the breakdown of starch molecules (polysaccharides) into maltose molecules (disaccharides) catalyzed by the digestive enzyme amylase.                                                         Many factors in a cell’s environment effect the action of an enzyme. The experiment of the effect of temperature on the enzyme amylase was performed to determine the correlation between the two. It was developed to test the enzymes reaction rate of digesting starch when it was unheated and after it had been heated.


Iodine and starch react to produce a dark blue colour so iodine may be used as an indicator to show the rate at which starch is broken down. By mixing the starch solution with the enzyme solution, (which we collected from our spit, that contains the enzyme amylase) the enzymes will slowly digest the starch to smaller units (maltose), and the iodine solution will turn yellow/brown.                         I know for a fact that most enzymes thrive best at a temperature around 40 °C, and around 45 °C they will start to be damaged. So therefore I predict: the amylase enzymes in our enzyme solution will not be able to break down the starch in our starch solution after having been heated, and therefore the iodine solution will remain dark blue.


What are enzymes?

Chemical reactions occur in all living organisms and are responsible for the proper maintenance and function of such organisms. Chemical reactions provide energy and nutrients and perform essential roles in the growth and survival of living systems. However, without any external forces, many of these necessary reactions that occur within cells and tissues would be highly inefficient and would not begin spontaneously.                                                                                                      Metabolism refers to all of the organized chemical reactions in a cell. Reactions in which chemical compounds are broken down are called catabolic reactions, while reactions in which chemical compounds are synthesized are termed anabolic reactions. All of these reactions are under the control of enzymes.                                                                                                                   Enzymes are substances found in all living organisms – whether animal or plant – that function to speed up or catalyze chemical reactions. They cause an increase in the rate of the reaction, while not being consumed in the reaction themselves.                                                                                        In a broad sense, there are two types of enzyme. Some that help join specific molecules together to form new molecules. Others that help break specific molecules apart into separate molecules.

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How do they function?

Enzymes are proteins, and, like all proteins, they consist of amino acids. Their molecules have a very precise three-dimensional shape. This shape includes a “dent” which is exactly the right size and shape for a molecule of the enzyme’s substrate to fit into. This is called the active site.  Enzymes perform only one specific job. That means an enzyme can do its job with very few side effects. It also explains why there are so many different types of enzyme.                               ...

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