IGESTION OF CARBOHYDRATES A. Enzymatic Hydrolysis of Starch A 1% solution of com
ID: 501473 • Letter: I
Question
IGESTION OF CARBOHYDRATES A. Enzymatic Hydrolysis of Starch A 1% solution of commercial a-amylase from human saliva (free from reducine, will be used here as the "saliva" sample. To test in the absence of enzyme (as a control): 1, with a mortar and peste. arind up a soda cracker and transfer to a 16 mm test tube. 2. Add 10 mL of water and place the tube in a 35-40 C water bath for 10 mi Sir frequently. 3. Filter the suspension, using vacuum filtration. 4. Test 1 mL of the filtrate for glucose as in Part IIC and another 1-mL portion for starch as in IIE. To test the effect of a-amylase, do this parallel experiment: l. In the mortar and pestle, grind up another soda cracker and transfer it to a 16 x 125-mm test 2. Add 10 mL of the "saliva" solution and place the tube in the 35-40 oC water bath for 10 minutes. Stir frequently. 3. Filter the suspension, using vacuum filtration; the equipment used above can be reused after rinsing and subsequent replacement of the filter paper. 4. Test 1 mL of the filtrate for glucose as in Part IIC and another 1-mL portion for starch asin Part IIE. Disposal: Pour remaining cracker suspensions in any sink and the test mixtures into organics" container. CarbohydratesExplanation / Answer
QUESTION 1
Iodine Test Benedict's Test No enzyme The triiodide anion in potassium iodide complexes with carbohydrates to give a blue-purple complex. Benedicts test does not react to starch,thus it retains the initial blue color. Enzyme The iodine solution remains dark brown. No change in colour. Benedicts reagent is blue and changes colour from yellow to orange when heated.