University:
Buffalo State University
Course:
CHE 111 | Fundamentals of Chemistry
Academic year:

2024
Views:

320

Pages:

2
Author:

ethan vicor

EXPERIMENT VI Enzymatic Hydrolysis of Starch 1.Enzymatic hydrolysis of starch by salivary amylase enzymes saliva is secreted by three pairs of salivary glands, namely glands parotid under the ear, submaxillary gland under the lower jaw sublingual gland under the tongue. This fluid consists of approx 0.5% non-water components. Two thirds of the components in the form of organic materials, especially ptyalin (amylase sativa) and mucin, meanwhile the remainder is in the form of inorganic ions such as SO4, P.O4, HCO3, Cl, Ca, Na and K. Musin in saliva it works when works This saliva is inactive at pH 4 or lower. Saliva generally has a pH slightly acidic, namely approximately 6.8. And 99.5% water and non water is as a lubricant food is chewed so hydrolyzes starch to oral cavity and moistens food easy to swallow. Ptyalin (salivary amylase) dextrins and maltose. 2. Saliva Sample Collection - Clean your oral cavity by gargling repeatedly. Chew a piece of cotton wool or filter paper moistened with a little acetic acid dilute, which aims to stimulate saliva production. Collect saliva up to 50 mL and filter with glass wool. 3. Hydrolysis of Starch by Salivary Amylase - Dab 2 mL of saliva (which has been filtered) in a 1% starch or starch solution and shake (in a test tube), then store or incubate at 37 oC (calledSolution I). Every 5 second interval, do an iodine test in the plate drops or petri dishes by taking one drop of sampleSolution I and mixed with one drop of Iodine reagent. Note when it appears opalescence and change in viscosity. Note down the seconds or minutes blue color, brownish color and when not shows another color change (remember the Iodine reagent itself is colored brownish). When the Iodine test no longer shows a positive test it is called Achromatic Point. Also do Benedict's test when the achromatic point is reached to ensure the formation of reducing sugars. - Compare the times you found for reaching the achromatic point with the time that other groups discovered. If this experiment is carried out at the same time and in the same way, are the results also the same? How? your comments? 4. Effect of pH on Saliva Amylase Activity Provide four test tubes and fill each with: 2 mL HCl 0.1% (Tube I), 2 mL Acetic Acid 0.1% (Tube II), 2 mL distilled water (Tube III) and 2 mL Na2CO30.1% (IV Tube). The pH value of each solution in these tubes are 1, 5, 7 and 9. Add 2 mL of 1% starch solution and 2 mL of saliva into each tube. Shake well and place on water bath 37oC for 15 minutes. Transfer the contents of the tube and divide it into two section, one section is subjected to the Iodine test and the other section is subjected to the Benedict's test. Explain the results of your experiment.