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Design an experiment in which you will investigate a digestive enzyme’s effect on digestion” Research Question: To determine the effect of enzyme concentration on the rate of digestion. This will be done by increasing the concentration of the enzyme diastase and investigate its effect on the rate of starch digestion. The rate will be determined by the amount of time it takes to completely digest the powdered starch, the complete digestion will be indicated by the color change of the solution by iodine.
Hypothesis: My hypothesis is that an increase in enzyme concentration will cause the faster suggestion of starch. This means that it will increase the rate of starch digestion. Background information explains that substrates bind to the active site of an enzyme by random movement of the molecules in liquids. An increase in enzyme concentration will increase the frequency of collisions that takes place between the substrates and enzymes, forming more substrate-enzyme complexes in a shorter time, meaning breaking down substrates in a shorter amount of time.
So we see here how an increase in the concentration of the enzyme diastase, will increase the rate of starch digestion. Though the amount of substrates can be a limiting factor, in that an increase in enzyme concentration will not cause any further increase in the rate of digestion, as there is no more substrate to be digested. Predictive Graph Sketch: This is the predictive grape sketch tot the e diastase on the rate of starch digestion.
Variables: Independent Variable: – Diastase enzyme concentration t tot concentration tot the enzyme The precision in the increasing of concentration of the diastase enzyme will be kept by ensuring the appropriate amount of powdered diastase dissolved in 100 ml of stilled water at controlled increments (1 gram increments from 1-5 grams). Dependent Variable: – Time it takes for starch to be completely digested (seen by color change) Controlled Variables: 1 . Temperature Temperature will be kept constant by not giving any treatment to the already standard school laboratory room temperature.
The experiment will be conducted in the same location at the same time to ensure temperature is controlled. All reactions will be held in the same temperature. 2. PH level pH level will be kept constant by ensuring all reactions in the experiment between amylase and starch occurs at the same PH. Since diastase works best at a pH of around 7, all reactions as diastase concentration is increased will be in a water medium. 3. Pressure Pressure will be kept constant by not giving any treatment to the already standard school laboratory room pressure.
So the experiment will be done in the same location at the same time to ensure the same height from sea level that will affect the pressure. 4. Starch concentration Substrate concentration will need to be controlled as it affects the rate of digestion as well. It will be controlled by ensuring the same concentration of starch powder suspended in water being reacted in the water medium with enzymes for all reactions. 5. Iodine Concentration Iodine solution concentration will be controlled as it affects the color intensity of the starch solution. I will ensure only two drops of Iodine will be used in all reactions.
Materials: Powdered starch Powdered diastase Distilled water Iodine solution Apparatus: Beaker (2) Timer (1) Laptop (1) Measuring Cylinder (1) Spatula (1) Pipette (1) Weighing Scale (1) Blue plastic dishes Design of equipment set up Procedure 1. Dissolve 1 gram of powdered Diastase in 100 ml of distilled water in a beaker 2. Suspend 5 grams of powdered starch in 100 ml of distilled water in a different beaker 3. Using a pipette, put two drops of Iodine solution on the suspended starch beaker and stir, this should give you a blue-black color 4.
Pour the dissolved diastase into the beaker with the suspended starch, and start timing immediately 5. The blue-black color should reside into the original Iodine brown color 6. Record the time it takes for the blue-black color to reside into the original Iodine brown color, this will mean that the dissolved starch has been completely digested 7. Calculate the rate of starch suggestion by dividing the initial concentration of dissolved starch over the time it takes for starch to be completely digested 8. Repeat steps 1-7 three times, multiple trials are needed to calculate the mean for a fair test 9.
Repeat steps 1-8 but dissolving 2 grams tot powdered Diastase in 1 ml tot distilled water in a beaker 1 Repeat steps 1-8 but dissolving 3 grams of powdered Diastase in 100 ml of distilled water in a beaker 11. Repeat steps 1-8 but dissolving 4 grams of powdered Diastase in 100 ml of distilled water in a beaker 12. Repeat steps 1-8 but dissolving 5 grams of powdered Diastase in 100 ml of distilled water in a beaker 13. Data will be presented in a properly constructed table and will be interpreted into a line graph showing the effect of diastase enzyme concentration on the time it takes to completely digest starch 14.