Introduction to Enzymes
The following has been excerpted from a very popular Worthington publication which was originally published in 1972 as the Manual of Clinical Enzyme Measurements. While some of the presentation may seem somewhat dated, the basic concepts are still helpful for researchers who must use enzymes but who have little background in enzymology.
Like most chemical reactions, the rate of an enzyme-catalyzed reaction increases as the temperature is raised. A ten degree Centigrade rise in temperature will increase the activity of most enzymes by 50 to 100%. Variations in reaction temperature as small as 1 or 2 degrees may introduce changes of 10 to 20% in the results. In the case of enzymatic reactions, this is complicated by the fact that many enzymes are adversely affected by high temperatures. As shown in Figure 13, the reaction rate increases with temperature to a maximum level, then abruptly declines with further increase of temperature. Because most animal enzymes rapidly become denatured at temperatures above 40°C, most enzyme determinations are carried out somewhat below that temperature.
Over a period of time, enzymes will be deactivated at even moderate temperatures. Storage of enzymes at 5°C or below is generally the most suitable. Some enzymes lose their activity when frozen.
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Biology: Experiment- The Effect of Temperature on the Enzyme Rennin
1881 WordsApr 20th, 20098 Pages
Aim: The aim of the experiment is to test the effect temperature has on the activity of the enzyme rennin.
Hypothesis: I believe the rate of reaction will speed up as the temperature increases until it reaches about 37oC, which is the body temperature, where it will begin to slow down and stop reacting. I believe this will occur because enzymes have a temperature range at which they work best in and once the temperature goes out of this range the enzyme will stop working.
Introduction:Enzymes are made up of proteins which are produced within living cells and act as catalysts which speed up chemical reactions. They are made up of long chains of amino acids containing carbon, hydrogen, oxygen and nitrogen. Enzymes are structured to be…show more content…
12.Stir then pour 2.5ml of the enzyme mixture into one of the test tubes not allowing any water from the saucepan into the test tube.
13.Start the stopwatch and time how long it takes to clot*.
14.Record time in table.
15.Repeat steps 9 12, changing the temperature to 20oC.
16.Repeat entire experiment one more time (or more if enough time).
*Clot: to test if it has clotted tilt the test tube and if the milk remains in the same shape, it has clotted.
-VariablesoIndependent:The temperature of the milkoDependent:The time taken for the milk to solidifyoControlled:The same amount and type of milk usedThe same amount and concentration of enzyme mixture usedThe same test tube sizeResults:-TableAmount of enzyme mixture (mL)Amount of milk (mL)Temperature (oC)Time for milk to clot (min)Ex: 1 Ex: 2 Average2.551060+60+60+2.552034.2036.0035.12.55303.554.203.882.55402.102.252.182.55505.004.454.73Discussion:The experiment showed that changing the temperature did affect the rate at which the milk solidified. At low temperatures of 10oC and 20oC the milk took the longest to solidify and at 10oC did not even go lumpy after an hour. As the temperature increased the speed at which it reacted got faster until it reached around 40oC where the speed began to drop.
Temperature controls the speed the enzymes work at. Higher temperatures increase the kinetic energy which increases the chance of collision therefore speeding up the rate of