Question

Which one is a polymer of fructose
(a) Glycogen
(b) Starch
(c) Inulin
(d) Raffinose

Answer 1

Fructose is a monosaccharide with a Pentose ring structure. When many monosaccharides are linked together they form a polymer or polysaccharides. For example, starch is a polysaccharide. In such a manner, Fructose forms a polymer that is seen in roots and rhizomes and certain vegetables like onions, leeks, and asparagus.

Complete Step by Step Answer:
Many fructose molecules polymerize to form a polysaccharide that is found in many fruits and vegetables such as onions, bananas, artichokes, leeks, and asparagus. This homopolymer of fructose is called ‘Inulin’. It is also formed in the roots and rhizomes.
These inulins belong to a class of dietary fibers known as fructans and it acts as a storage molecule in many plants.
So, the correct answer is, “Inulin”.

Additional Information:
- Industrially inulin is obtained from a woody plant known as chicory.
- Inulin is not absorbed or metabolized in the body and is excreted in the urine without any change. So, it is used as an effective method to measure kidney function and glomerular filtration rate or GFR.
- Starch is a homopolymer of glucose that is formed by a linear arrangement of the glucose molecules. It is used as a storage material in plants and is present in the food, which is broken down during digestion.
- Glycogen is also a homopolymer of glucose which is used as the storage molecule in animal cells. It is different from starch as it shows branching in its structure.
- Raffinose is not a polysaccharide but a trisaccharide which is made up of one molecule each of glucose, galactose, and fructose. It is present in cabbage, broccoli, asparagus, etc.

Note:
- Inulin must not be confused with insulin
- The former is a polysaccharide made of fructose whereas the latter is a peptide hormone formed in our body.
- Insulin is a peptide hormone that is essential for the breakdown of Glucose and it helps in the regulation of blood sugar levels.