BIOMOLECULES AND ENZYMES

Detailed explanation-1: -In general, blue to blue-green or yellow-green is negative, yellowish to bright yellow is a moderate positive, and bright orange is a very strong positive.

Detailed explanation-2: -Using an iodine solution, you can test for the presence of starch. When starch is present, the iodine changes from brown to blue-black or purple.

Detailed explanation-3: -If adding Benedict’s reagent in the glucose solution and then heating it, the solution changes gradually from blue to dark orange. That is, colors change in the order of blue-green-yellow-dark orange according to the concentration of glucose.

Detailed explanation-4: -A positive result for the iodine test (starch is present) was a colour change ranging from violet to black; a negative result (no starch) was the yellow colour of the iodine solution.