Question

Select the correct statements related to carbohydrates: (A) Glucose is also known as dextrose. (B) In glucose, an aldehydic group is present and it gives Schiff's test. (C) Glycogen is also known as animal starch. (D) Lactose is a reducing sugar.

• A. (A), (B) and (D) only
• B. (A), (B) and (C) only
• C. (A), (C) and (D) only
• D. (B), (C) and (D) only

Hint:

Lactose and maltose are reducing sugars, whereas sucrose is a non-reducing sugar because both anomeric carbons are involved in glycosidic bond formation.

Answer 1

The Correct Option is C

Concept: Carbohydrates possess characteristic structural and chemical properties that help in their identification and classification.

Step 1: Examine statement (A).
Glucose is commonly known as dextrose. Hence statement (A) is correct.

Step 2: Examine statement (B).
Although glucose exists in equilibrium with an open-chain aldehyde form, it does not give Schiff's test readily because the concentration of free aldehydic form is extremely small. Therefore statement (B) is considered incorrect.

Step 3: Examine statement (C).
Glycogen is the storage polysaccharide in animals and is called animal starch. Hence statement (C) is correct.

Step 4: Examine statement (D).
Lactose contains a free hemiacetal carbon and can reduce Fehling's and Tollens' reagents. Therefore lactose is a reducing sugar. Hence statement (D) is correct.

Step 5: Select the correct combination.
Correct statements are: \[ (A),\ (C),\ (D) \] Hence option (C) is correct.