Question

Dehydration reaction is observed in the formation of all except

• A. Cystine
• B. Lecithin
• C. Adenosine
• D. Collagen

Answer 1

The correct option is D Collagen

Dehydration reactions involve the loss of water. These reactions commonly occur during the attachment of two units through the H molecule of one unit and OH unit of the other unit. In such process, water is removed.

A. Cystine is formed by the addition of two cysteine molecules via a disulfide bond. Water is removed in disulfide bond formation. So, dehydration reaction occurs.

B. Lecithin is a type of fat molecule which is formed by the ester bonds in which water is removed. It is a dehydration reaction.

C. Adenosine is formed by the addition of adenine residue to the ribose sugar by the glycosidic bond which is also a dehydration reaction.

D. Collagen is formed from the procollagen made up of vitamin C and proteins. Procollagen result in the formation of collagen via the aldol reaction. It is not a dehydration reaction.

Hence, the correct answer is 'Collagen'