Which of the following classifications of carbohydrates produces glycosidic linkage?

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2022

Explanation

Monosaccharides are the simplest sugar units and serve as the fundamental building blocks (monomers) for more complex carbohydrates.
The formation of a glycosidic linkage is a chemical reaction known as dehydration synthesis, where two monosaccharide molecules join together.
During this reaction, a water molecule is eliminated, and a covalent bond, the glycosidic bond, is produced, linking the two units.
Thus, monosaccharides are the reactants that directly participate in the reaction to 'produce' the linkage.

Option B: Disaccharides are the product of two monosaccharides joining. They are defined by already containing one glycosidic linkage, not producing it.
Option C: Polysaccharides are large polymers made of many monosaccharides. They are complex structures that contain numerous glycosidic linkages.
Option D: Oligosaccharides are short chains of 3-10 monosaccharides. Like disaccharides and polysaccharides, they are molecules that already contain multiple glycosidic linkages.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Formation of glycosidic bonds in carbohydrate chemistry as background academic context rather than a clinical decision trigger.
Understanding glycosidic bonds is crucial for comprehending digestion. Digestive enzymes like amylase and lactase work by breaking these bonds (hydrolysis) to release monosaccharides (like glucose) for absorption into the bloodstream.
What if? If a person lacks the enzyme lactase, they cannot break the beta-1,4 glycosidic bond in lactose (milk sugar). This leads to lactose intolerance, with symptoms of bloating, gas, and diarrhea as gut bacteria ferment the undigested sugar.

How to Approach the Question

First, identify the key action word in the question: 'produces'. This asks about the process of creation or formation.
Next, recall the basic definitions of the carbohydrate classes. Monosaccharides are the simplest units (monomers).
Disaccharides, oligosaccharides, and polysaccharides are all larger molecules made by joining monosaccharides together.
Reason that to 'produce' a link, you must start with the basic building blocks. Therefore, the monosaccharides are the units that react to produce the glycosidic linkage.
Eliminate the other options as they are the results of this process and already contain the linkages.

Concept Tested & Keywords

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E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 1 (pp 26-370 of 370) p. 76-78

E6 Biochemistry U Satyanarayana— Part 1 (pp 26-420 of 840) p. 1

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