Question

Ribose and 2- deoxyribose can be differentiated by:
(A) Fehling’s reagent
(B) Tollen’s reagent
(C) Barfoed’s reagent
(D) Osazone formation

Answer 1

Hint: Both ribose and deoxyribose are very important biomolecules present in the body of an organism. To answer this question, you must recall the difference in the structure and properties of these two monosaccharide compounds. Also, you must recall the reactions occurring when ribose and 2- deoxyribose are reacted with the given reagents in the compounds. The reaction in which only one of the given molecules reacts selectively or changes like change in colour, precipitation, formation of crystals etc. are observed can be used to distinguish them.

Complete step by step solution
The only difference between ribose and 2- deoxyribose is that the 2- deoxy ribose molecule contains one oxygen atom less than the ribose molecule. The hydroxyl group on the second carbon atom in ribose is replaced by a hydrogen atom to give 2- deoxyribose. Due to the absence of this hydroxyl group, deoxyribose cannot form osazone while ribose can.

Osazone crystallizes readily and thus the change can be visually determined.
The correct answer is D.

Note
The nuclear material present inside the nucleus of a cell of an organism decides the physical traits of that organism. The nuclear material is composed mainly of deoxyribo- Nucleic Acid (DNA) or ribo- Nucleic Acid (RNA). The DNA present in the nucleus of every cell decides and controls all the various biochemical reactions and the physical features of the organism. Each organism has their own specific set of nuclear material (DNA) that provides information to other cell organelles to perform their functions. DNA is mainly composed of 5- carbon simple sugar molecules. The molecule has two different forms and they construct two different structures DNA and RNA in the nucleus of every cell.