Starch could be converted to glucose by the process of

Step 1: Analyze the question We are asked which process converts starch (a polysaccharide) into glucose (a monosaccharide), that is, a large molecule broken down into its small building units.

Step 2: Explain the concept Starch is a polymer made of many glucose units joined by glycosidic bonds. To break these bonds, water is added across them. This process is called hydrolysis ("hydro" = water, "lysis" = splitting).

(C₆H₁₀O₅)ₙ + nH₂O → nC₆H₁₂O₆ (starch + water → glucose)

The reaction is catalysed by dilute acid (e.g. dilute HCl or H₂SO₄ with heating) or by enzymes such as amylase.

Step 3: Check each option

• A. Condensation: This is the opposite process. Small units join together and release water, as when glucose units form starch. ✗
• B. Dehydration: This is the removal of water from a compound, such as ethanol to ethene using concentrated H₂SO₄. It does not break starch into glucose. ✗
• C. Fermentation: This is the enzyme-catalysed breakdown of glucose into ethanol and carbon dioxide (using zymase in yeast). It starts from glucose rather than producing it. ✗
• D. Hydrolysis: Water splits the starch polymer into glucose units. ✓

Step 4: Answer The correct option is D. Hydrolysis.

Exam tip: Remember the pathway: Starch → (hydrolysis) → Glucose → (fermentation) → Ethanol + CO₂

Hydrolysis breaks big molecules down with water, while condensation builds them up and releases water.