Question

Explain the Testing pH of mouth at intervals of one hour with Aim , material required , procedure , readings , precautions , observations .

Help me please​

Answer 1

Answer:

Aim

Effect of Different pH on the Activity of Salivary Amylase on Starch

Materials Required

Three series of test tubes having iodine solution in each, test tubes, pH tablets of 5, 6.8 and 8, beaker containing water with thermometer, 15 ml 1% starch solution + 3 ml 1% NaCl, saliva solution, droppers, Bunsen burner and wire gauze.

Real Lab Procedure

Take a beaker containing 15 ml of 1% starch solution + 3 ml of 1% NaCl solution.

Divide and pour this solution into three test tubes and mark them as A, B and C.

Add pH tablet 5 into test tube A, pH tablet 6.8 into test tube B and pH tablet 8 into test tube C.

Now transfer experimental tube A, B and C into a beaker containing water and a thermometer for recording temperature. Temperature of this beaker is to be maintained at 37°C.

Using a dropper, take 3 ml saliva solution and add 1 ml of solution to each of the three test tubes.

Immediately using a dropper, take few drops from experimental tube A and transfer this into the first series of test tubes having iodine solution.

Similarly, do the same procedure for test tube B and test tube C and transfer the solution into second and third series of test tubes having iodine solution.

Note this time as zero minute reading.

After an interval of 2 minutes, again take a drop from each tube and add to the iodine tubes and note the change in colour of iodine.

Keep on repeating the experiment at an interval of every 2 minutes till colour of iodine does not change.

Results

pH 5 is acidic and pH 8 is alkaline, therefore salivary amylase did not act in these tubes. Whereas, the enzyme acted in the tube with pH 6.8 (i.e., slightly acidic) and digested the starch.