Carbohydrates

Concept: Mutarotation occurs in reducing sugars having free anomeric carbon.

Step 1: Glucose, ribose, and fructose are reducing sugars.

Step 2: Sucrose is non-reducing (no free anomeric carbon).

Step 3: Hence sucrose does not show mutarotation.
Conclusion:
Correct answer = Sucrose

Concept: Osazone formation depends only on first two carbons.

Step 1: Osazone reaction involves C-1 and C-2.

Step 2: Differences beyond C-2 are ignored.

Step 3: Structures I and III differ only at C-1/C-2.
Conclusion:
I and III give same osazone.

Concept: Anomers are stereoisomers differing at the anomeric carbon.

Step 1: Anomers differ at anomeric carbon.

Step 2: They are not mirror images not enantiomers.

Step 3: Hence, they are diastereomers.
Conclusion:
Correct answer = Diastereomers