Enzymes

Introduction:

Enzymes are an important part of all metabolic reactions in the body. They are catalytic proteins, able to increase the rate of a reaction, without being consumed in the process of doing so (Campbell 96). This allows the enzyme to be used again in another reaction. Enzymes speed up reactions by lowering the activation energy, the energy needed to break the chemical bonds between reactants allowing them to combine with other substances and form products (Campbell 100). In this experiment the enzyme used was acid phosphates (ACP), and the substrate was p-nitrophenyl phosphate.

Enzymes are very specific in nature, which helps them in reactions. When an enzyme recognizes its specific substrate, the enzyme binds to the substrate in a region called the active site which is made of amino acids. Once the substrate binds, the enzyme changes its shape slightly to make an even tighter fit around the substrate, This is called induced fit and it allows for the enzyme to catalyze the reaction more easily. Another factor contributing to catalyses is the amount of substrate present; the more substrate molecules available, the more often they bind the active site. Once all of the enzyme's active sites are occupied by substrate, the enzyme is saturated ( Campbell 99). Enzyme's have optimal conditions under which they perform. These include temperature, pH, and salt concentration, amongst others. In this lab we only focused on pH and temperature. Each enzyme is specific to a certain optimal temperature and pH. When conditions are favorable, the reaction takes place at a faster rate, allowing for more substrates to collide with active sites of enzymes. However, if conditions get too extreme, the enzyme...

... middle of paper ...

...eadings. The absorbance readings for test tube 5, were always further away from the expected values than test tube 1. This is because the NaOH was not added to each tube at a time, but in sequential order with the test tube numbers. This allowed the reaction in test tube 5 to proceed longer than in test tube 1, allowing more product to be produced, giving a higher absorbance reading than expected. In fact, this trend was shown in all the test tubes. In increasing order of test tube numbers, every absorbance was more off than expected.

I would change a few things about this lab. Firstly, I would have used a micropipette instead of the ones that we used because they would give more precise measurements. Also, I would have had five people in each group so that everyone could add NaOH to the solutions at the same time, stopping the reactions simultaneously.