The number of chiral carbons present in sucrose is ………………… . — Biomolecules Chemistry Question

💡 Solution & Explanation

**Step 1: Identify the structure of sucrose** Sucrose is a disaccharide composed of glucose (C₆H₁₂O₆) linked to fructose (C₆H₁₂O₆) through a glycosidic bond. **Step 2: Count chiral carbons in glucose** Glucose has 4 chiral carbons. These are the carbons bearing four different groups: - C2, C3, C4, and C5 are chiral - C1 becomes part of the glycosidic bond but remains chiral in sucrose - Total in glucose unit: 5 chiral carbons **Step 3: Count chiral carbons in fructose** Fructose has 3 chiral carbons: - C3, C4, and C5 are chiral - C2 is a ketone carbon (not chiral) - C1 becomes part of the glycosidic bond but remains chiral in sucrose - Total in fructose unit: 4 chiral carbons **Step 4: Account for the glycosidic bond** The C1 of glucose and C2 of fructose form a 1,2-glycosidic bond. Both carbons retain their chiral centers even after bond formation. **Step 5: Calculate total chiral carbons** Total = Chiral carbons from glucose + Chiral carbons from fructose Total = 5 + 4 = 9 Therefore, the answer is 9.00.