Use the following information to answer the question below. I. Test tube containing cane sugar and water . ll…

Analyze the question Cane sugar is sucrose, a disaccharide made of glucose and fructose. The question asks in which test tubes sucrose is hydrolysed, so that glucose is released.

Explain the concept Hydrolysis of sucrose means breaking the glycosidic bond using water. This happens when:

• Dilute acid is heated or present (acid hydrolysis), or
• The enzyme sucrase (invertase) is present (enzymatic hydrolysis).

Sucrose + water → glucose + fructose

Plain water alone does not break down sucrose at any meaningful rate. Sucrose is stable in water at ordinary conditions.

Step-by-step solution

• Tube I (cane sugar + water): No catalyst, so no hydrolysis. No glucose.
• Tube II (cane sugar + dilute acid): The acid catalyses hydrolysis, so glucose and fructose are produced.
• Tube III (cane sugar + its degrading enzyme): Sucrase catalyses hydrolysis, so glucose and fructose are produced.

Glucose will be detected in tubes II and III only.

Answer: B

Exam tip: Remember that hydrolysis needs a catalyst, either an acid or an enzyme. Water alone is a reactant, but it does not start the reaction. Also, sucrose itself is a non-reducing sugar, so it only gives a positive Benedict's test after hydrolysis.