BIOL2930 17 S2 LAB 10 DIGESTIVE ENZYMES POST-LAB [Compatibility Mode] Mailings R
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BIOL2930 17 S2 LAB 10 DIGESTIVE ENZYMES POST-LAB [Compatibility Mode] Mailings Review View Normal Heading 1No Spacing Heading 2ide Experiment #1: You conduct an experiment to investigate the effects of temperature and pH on the action of amylase, an enzyme that digests carbohydrates. After incubating your samples for 1 hour, you use iodine to test for the presence of starch and Benedict's reagent to test for the presence of digested product. Results from this experiment are presented in Table 1 below. Use the data below to answer questions 1 & 2. This is similar to what you did in lab. Refer to your notes. Table 1: Experiment 1 Results Test Tube # 1 2 Test Tube Contents lodine Test Purple-black tarch + saliva mix (amylase) + HCI Purple-black Starch+boiled saliva mix (amylase) Purple-black Benedict's Test No change (blue No change (blue) Orange Starch + water Starch +saliva mix lamylase) HC!Purple-black Starch + saliva (amylase) No change (brown) Red (3pts] Based on the results in Table 1, which tube has the highest amount of digested product? Explain what pieces of evidence you have. 1. a. (2pts] Based on the results in Table 1, which tube has partial digestion? Explain what pieces of evidence you have. b. (2pts] Why wasn't there complete digestion in this tube? 2.Explanation / Answer
1. Iodine (brown in color) reacts with starch to give blue black colour. Iodine in absence of starch retains its brown color. Benedicts test is used to detect the reducing sugar concentration in a solution. Change in color to green indicates very low reducing sugar, yellow indicates low reducing sugar, orange indicates moderate reducing sugar and red indicates highest level of reducing sugars. Starch does not reacts with benedicts reagent and thus there is no colour change.
As we can see from the experiment, 4th sample i.e. starch + saliva gives iodine its brown color and benedicts reagent red color, it has the highest amount of reducing sugar in it.
When saliva is boiled high temperature denatures the enzymes. When saliva is mixed with acid the enzymes will not work due to acidic medium. Saliva needs neutral pH to break down starch.
2.a) partial digestion is seen in 3rd tube starch + boiled saliva. Reaction with benedict solution shows orange colour which indicates presence of reducing sugars.
b) boiling of saliva led to denaturing of amylase enzyme which led to partial digestion.
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