Temperature and pH have large effects on the enzymatic activity of alpha amylase. This was determined by measuring the reaction rates by varying the temperatures and pH of a reaction.
Figure 1 indicates that as the temperature increases the reaction rate increases. When the reaction rate reaches its maximum level this indicates the optimum temperature. The optimum temperature is where the enzyme preforms at its highest capacity. The optimum temperature in relation to this experiment was 37°C. This is expected because this reaction takes place in the human body which has a temperature of 37°C. Below or above this temperature the enzyme loses its ability to function (Santhosh, (2016)).
Enzymes are only active over a slight pH range at this point it is where the reaction occur at its fastest. The optimum pH of the reaction is 6.8. pH-activity relationship with enzymes relies on having side chains of amino acids already existing in the enzyme (Rodillas et al. (no date)). The optimum pH differs from enzyme to enzymes and depending on the type of enzyme. Minor changes in pH above or below the optimum do not cause a permanent change to the enzyme as bonds can be reformed. If the change in pH is extreme then this can cause enzymes to denature and could lose their functions permanently (Boundless (2016)).
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The activity of enzymes may be markedly changed by any alteration in pH, which in turn, alters electrical charges on the enzyme (Rodillas et al.
(no date)). Ionic bonds can be affected by changes in charge. These ionic bonds contribute to the enzymes tertiary and quaternary structure. The proteins configuration and activity would thereby be changed (Rodillas et al. (no
date)). Temperature and pH have a big effect on the enzymatic activity of alpha amylase. Changing the temperature and pH in a reaction have a large effect on the efficiency and effectiveness of an enzyme. Enzymes need the correct temperature and pH to function at their highest capacity. There were slight inconsistencies when it came to measuring the time during the experiment. This became a problem when adding the iodine to the reaction mixture. The timing of exactly 30 seconds was not exact every time. This could be overcome by repeating the experiment a number of times and then taking the average of those results. This would help to obtain a more accurate result. The results that were found in this experiment were similar to the results that previous researchers have arrived at. These researchers (Sarah (2014)) have stated an optimum temperature of 37°C to 37.5°C. In relation to this optimum pH there seems to be a small window for the optimum pH, being between 6 and 7. The result of our experiment indicates that it is 6.8 (Figure 2). The experiment can be progressed from here by looking at the effect that the enzyme and substrate concentrate have on the enzymatic activity. Thus further providing us with information of how an enzyme will perform most effectively at its peak level.
This indicated that the effect of high temperature on the activity of peroxidase was irreversible and so if the optimum temperature was restored the enzyme activity will not increase again because denaturation resulted in a permanent change in the shape of the active site of the peroxidase enzyme. In conclusion, the results of this experiment supported the hypothesis that enzymes including peroxidase enzyme are sensitive to temperature changes[George
The affects of pH, temperature, and salt concentration on the enzyme lactase were all expected to have an effect on enzymatic activity, compared to an untreated 25oC control. The reactions incubated at 37oC were hypothesized to increase the enzymatic activity, because it is normal human body temperature. This hypothesis was supported by the results. The reaction incubated to 60oC was expected to decrease the enzymatic activity, because it is much higher than normal body temperature, however this hypothesis was not supported. When incubated to 0oC, the reaction rate was hypothesized to decrease, and according to the results the hypothesis was supported. Both in low and high pH, the reaction rate was hypothesized to decrease, which was also supported by the results. Lastly, the reaction rate was hypothesized to decrease in a higher salt concentration, which was also supported by the results.
The alternate hypothesis is that there exists an optimal pH level for catecholase enzyme in which the catecholase enzyme can operate with the highest possible
The effect of a change in PH on enzymes is the alteration in the ionic
The shape of the molecules is changing and so the enzyme molecules can no longer fit into the gaps in the substrate that they need to and therefore the enzymes have de – natured and can no longer function as they are supposed to and cannot do their job correctly. Changing the temperature: Five different temperatures could be investigated. Water baths were used to maintain a constant temperature. Water baths were set up at 40 degrees, 60 degrees and 80 degrees (Celsius). Room temperature investigations were also carried out (20 degrees).
or it may be optimum it depends on what is the best pH that the enzyme
Jim Clark. (2007). The effect of changing conditions in enzyme catalysis. Retrieved on March 6, 2001, from http://www.chemguide.co.uk/organicprops/aminoacids/enzymes2.html
The independent variable for this experiment is the enzyme concentration, and the range chosen is from 1% to 5% with the measurements of 1, 2, 4, and 5%. The dependant variable to be measured is the absorbance of the absorbance of the solution within a colorimeter, Equipments: Iodine solution: used to test for present of starch - Amylase solution - 1% starch solution - 1 pipette - 3 syringes - 8 test tubes – Stop clock - Water bath at 37oc - Distilled water- colorimeter Method: = == ==
In this experiment as a whole, there were three individual experiments conducted, each with an individualized hypothesis. For the effect of temperature on enzyme activity, catalase activity will be decreased when catalase is exposed to temperatures greater than or less approximately 23 degrees Celsius. For the effect of enzyme concentration on enzyme activity, a concentration of greater or less than approximately 50% enzymes, the less active catalase will be. Lastly, the more the pH buffer deviates from a basic pH of 7, the less active catalase will be.
However, the decrease varied depending on the temperature. The lowest temperature, 4 degrees Celsius, experienced a very low decrease of amylose percentage. Temperature at 22 degrees Celsius and 37 degrees Celsius, both had a drastic decrease in amylose percentage. While the highest temperature, 70 degrees Celsius, experienced an increase of amylose percentage. In conclusion, as the temperature increases the percentage of amylose decreases; however, if the temperature gets too high the percentage of amylose will begin to increase. The percentage of amylose increases at high temperatures because there is less enzyme activity at high temperatures. However, when the temperature is lower, more enzyme activity will be present, which results in the decrease of amylose percentage. This is why there is a decrease of amylose percentage in 4, 22, and 37 degrees Celsius. In this experiment the optimal temperature is 37 degrees Celsius, this is because this is the average human body temperature. Therefore, amylase works better at temperatures it is familiar
The temperature of the reaction, as some of the energy produced converts into heat energy. At really high temperatures the reaction will stop because the heat will have denatured the enzymes.
Enzymes have the ability to act on a small group of chemically similar substances. Enzymes are very specific, in the sense that each enzyme is limited to interact with only one set of reactants; the reactants are referred to as substrates. Substrates of an enzyme are the chemicals altered by enzyme-catalysed reactions. The extreme specific nature of enzymes are because of the complicated three-dimensional shape, which is due to the particular way the amino acid chain of proteins folds.
Two environmental factors can effect enzyme activity: pH and temperature. Changes in the pH can alter the level of hydrophobicity of some regions of a protein, thus altering its shape. If the enzymes shape is altered then it will not bind with its receptor. Temperature also affects enzyme activity. All enzymes perform best at their optimal temperature. In addition, each enzyme has a minimum and maximum temperature at which it can successfully perform. Substrate concentration can chemically
In this lab, it was determined how the rate of an enzyme-catalyzed reaction is affected by physical factors such as enzyme concentration, temperature, and substrate concentration affect. The question of what factors influence enzyme activity can be answered by the results of peroxidase activity and its relation to temperature and whether or not hydroxylamine causes a reaction change with enzyme activity. An enzyme is a protein produced by a living organism that serves as a biological catalyst. A catalyst is a substance that speeds up the rate of a chemical reaction and does so by lowering the activation energy of a reaction. With that energy reactants are brought together so that products can be formed.
From looking at the results I can conclude that when the pH was 3 and 5. No oxygen was produced, therefore no reactions were taking place. This was because the pH had a high hydrogen ion content, which caused the breaking of the ionic bonds that hold the tertiary structure of the enzyme in place of the syringe. The enzyme lost its functional shape.