Effect of Enzyme Concentration - Lab Report Example

? Lab 4: Enzyme Experiment Effect of enzyme concentration Data Table Effect of enzyme concentration on the production of gas Response to Question 1 Enzyme-Catalase produced by the yeast Substrate-Hydrogen peroxide Response to Question 2 The rate of reaction in tube 1 was rapid followed by tube 2 and in tube 3 it was the slowest. This difference was because of the differences in the concentration of yeast cells that produces catalase enzyme directly proportion to the amount in each tube. The higher the concentration of catalase enzyme the higher the rate of reaction and vice versa. In other words the more yeast put in the Hydrogen Peroxide the more violent the reaction; therefore, giving off more oxygen. This is because of the reaction theory (the rate of a reaction depends on how often and how hard the reacting particles collide with each other) Response to Question 3 As the concentration f the enzymes decreases, so does the speed and vigor of the reaction. This is evidenced from the low volume of oxygen produced in tube 3 with less enzyme concentration. As the enzyme concentration decreases, the rate of reaction also decreases because there are fewer enzymes present to break down the substrate. Response to Question 4 More enzyme activity is expected if the substrate concentration is decreased. When there are low concentrations of substrate there is a linear relationship between the reaction rate and substrate concentration. In these conditions the relation of catalase enzyme to hydrogen peroxide substrate molecules is high. Experiment 2: Effect of temperature on enzyme activity. Data Table 2: Effect of temperature on the production of gas Tube Temperature ?C Balloon diameter (cm) Refrigerator 6 5.0 Room temperature 23 12.5 Hot water 90 1.0 Response to Question 1 The enzyme in this experiment is catalase enzyme and hydrogen peroxide is the substrate. Response to Question 2 The rate of enzyme catalyzed reaction tends to increase with the increasing temperature of reaction medium. Enzymes are known to be proteins, they are gradually denatured thus lose their activity at the temperatures beyond their optimum temperature. In this case, catalase enzyme’s maximum activity is around 37? degrees Celsius. At extremely low temperatures, the reactants move around slower because of having less kinetic energy. This means that collisions occurring between the substrate and catalase enzyme active site happen less resulting in reduced enzyme-substrate complexes, therefore, slow down the reaction. An increase in temperature causes the reactants to have more kinetic energy. They, therefore, end up moving around faster and the movements cause more collisions between the substrate and active site of the enzyme. Therefore, there shall be more enzyme-substrate complexes taking place hence speeding up the reaction. Temperatures above the optimum alter the shape of the active site of enzymes. This causes the temperature to denature the enzyme. In effect, enzyme-substrates would not be created due to the substrate not fitting in the active site. Denaturing the enzyme would mean that the tertiary structure is altered, which would end up causing the reaction process to stop completely. Response to Question 3. Yes plants and animals have the enzymes that breakdown hydrogen peroxide. Response to Question 4 Maintaining an optimum temperature of about 37 degrees Celsius increases the enzyme activity. Response to Question 5. The presence of catalase enzyme in cells catalyses the toxic hydrogen peroxide to non toxic products that include, water and Oxygen. Hydrogen Peroxide ----–catalase enzyme---- Water + Oxygen. Response to Question 6 Experiment to determine the optimal temperature for enzyme function The experiment would be set up as below. First, set up the water bath; secondly, place a thermometer in the water bath so that the proper temperature is maintained. 0-5degrees Celsius: 400mL beaker to be filled with water and ice 20-25 degrees Celsius: No water bath is required to maintain the room temperature. 30-35 degrees Celsius: 400mL beaker to be filled with very warm water. 50-55 degrees Celsius: 400 mL beaker to be filled with hot water. The next step is to rinse the 3 test tubes that are numbered and used in part 1. Follow it by filling each test tube with about 5 mL of the 3.0% hydrogen peroxide and 5 mL of water. Put the test tubes in a water bath making sure the test tubes are maintained in the water bath for about five minutes before moving to the next step. Record the water bath temperature as seen on the thermometer in the table. 2. Finding the enzyme rate of activity for the test tube 1, 2, and 3. Add 8 drops of the enzyme solution into the test tube 1and repeat all the above steps Add 8 drops of an enzyme solution into the test tube 2 and repeat the steps in 1 Add 8 drops of an enzyme solution into the test tube 3 and repeat the two immediate steps above. 3. Do a repeat of Step 2 while recording the reaction rates for each of the data sets in the table. Then calculate and record average rates in the table. The substrate in this experimental set up is hydrogen peroxide and the control experiment involves using a boiled potato following the same change in temperature. Experiment 3: Enzymes in food. Response to Question 1 Saliva contains enzyme amylase whose function is to breakdown starch into simpler sugars that are later broken to produce energy Response to Question 2 The control experiment should make use of water instead of the starch solution following the same procedure. This is because water has no starch. Response to Question 3 Five minutes period allows the salivary amylase to work on starch if at all it is present. Response to Question 4. Foods found to contain starch include potatoes and bananas while foods that lack starch are the ginger roots and the apples. For the potatoes and bananas, the color of iodine changed to dark purple, while for ginger roots and apples, the color for iodine remained unchanged. Response to Question 5. The additional digestive enzyme secreted by salivary glands is salivary lipase. The enzyme is produced in the mouth with a pH optimum of ~4.0. Thus, it stays neutral while in the mouth until it reaches the mouth which has acidic conditions necessary to activate the enzyme to digest fat. This enzyme is, therefore, responsible for fat digestion in the newborn infants. This is because the pancreatic lipase of the newborn infants still requires some time to develop fully. This enzyme also has a protective function. In this case, it helps in preventing bacterial build-up along the teeth, as well as washing away the adhered food particles. Response to Question 6 Given that babies of about two months old lack amylase, which is an enzyme that aids in starch digestion they are incapacitated to consume cereals. The diet of the baby is somewhat iron-poor since breast milk is by design iron-poor thus grains do interfere with iron absorption (Robert, 1998). Moreover, cereals do not provide high quality proteins and fats for the baby. This implies that giving them cereals is likely to interfere with their digestive system. Response to Question 7 There are other household uses of enzymes. First, enzymes are widely used in preparation of fabrics for household furniture, clothing, and other items. Secondly, enzymes enhance the preparation of cotton to be used for weaving. In line with this, they help reduce impurities, and act as pre-treatment before dying to help reduce the rinsing time and in improving the color quality. Thirdly, the enzymes present in the yeast and bacteria are utilized in making wine, cheese, beer, and vinegar. Lastly, enzymes are used in pulp and paper industries in removing adhesives, coating, and glues. Response to Question 8 There are two reasons that prevent digestive enzymes such as proteases from damaging the stomach and small intestines, which partially are both made of protein. First, pepsin is only active as an enzyme under sheer acidic conditions like those in the stomach. This implies that the moment the stomach chyme is dumped into the duodenum, the PH is drastically increased, and this makes the pepsin be denatured. Hence the enzyme is no longer active for the digestion of protein. Secondly, the pepsin enzyme is only found in the stomach, where it is always compartmentalized from the other body areas. The mucus membrane in the stomach helps in protecting the stomach lining to make sure the stomach is not in any way degraded by the enzyme (Simon, Eric & Jean (2013). References Simon, N, Eric, J, & Jean, L. (2013). Campbell Essential Biology (5th Edition). Retrieved on 8th Oct 2012 from www.amazon.com. Read More