Question 4
An experiment was conducted using a Visking tubing shown in Figure 3.1. The Visking tubing is a selectively permeable membrane which only allows small molecules to pass through.
A starch molecule is made up of many, small glucose molecules chemically bonded together.
Figure 3.1
After 3 hours, 1mL of the liquid in the test-tube was pipetted up using a dropper. This liquid was used in Iodine test. The iodine test is to test for the presence or absence of starch. Another 1ml of the liquid in the test tube was then pipetted up using a dropper. This liquid was used in Benedict’s test. Benedict’s test is to test for the presence or absence of glucose.
a. Explain the results of the two tests that were conducted for the liquid in the test-tube. [3 points]
b. Suggest one method to shorten the time taken to obtain the results shown in Figure 3.1 [1 point]
A starch molecule is made up of many, small glucose molecules chemically bonded together.
Figure 3.1
After 3 hours, 1mL of the liquid in the test-tube was pipetted up using a dropper. This liquid was used in Iodine test. The iodine test is to test for the presence or absence of starch. Another 1ml of the liquid in the test tube was then pipetted up using a dropper. This liquid was used in Benedict’s test. Benedict’s test is to test for the presence or absence of glucose.
a. Explain the results of the two tests that were conducted for the liquid in the test-tube. [3 points]
b. Suggest one method to shorten the time taken to obtain the results shown in Figure 3.1 [1 point]