Question 39 of 49
Q.(i) Deficiency of which vitamin causes pernicious anaemia?
(ii) Between sucrose and maltose, which is a reducing sugar?
(iii) Write with chemical equation what happens when D-glucose is treated with bromine water. (1+1+1)
West Bengal WbchseWest Bengal HS (WBCHSE) Board 2023Subjective· 3mImportance★★★★★
80% · 39/49 Questions
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Start your 14-day free trial to unlock the full solution →B12 deficiency causes pernicious anaemia; maltose has a free anomeric -OH so it reduces Fehling's/Tollens' reagent, sucrose does not; bromine water mildly oxidises glucose's aldehyde group.
- A deficiency of Vitamin B12 (cobalamin) impairs red blood cell maturation and causes pernicious anaemia.
- Maltose is formed from two glucose units joined by an alpha-1,4-glycosidic bond, leaving one anomeric carbon free with its -OH group intact (a potential aldehyde/hemiacetal); this free reducing end lets maltose reduce Fehling's and Tollens' reagents, making it a reducing sugar. Sucrose, by contrast, is formed by a glycosidic bond between the anomeric carbons of BOTH glucose and fructose, leaving no free anomeric -OH — it cannot reduce Fehling's/Tollens' reagent and is a non-reducing sugar. …
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