Question

A nonreducing sugar is
A) Glucose
B) Sucrose
C) Fructose
D) Maltose

Answer 1

Hint: It is usually called cane sugar and forms when glucose and fructose combine together. Plants use it as a depositary molecule. It is also important for humans as it is easily taken out from the plants.

Complete step by step answer:
Non reducing sugar-It is a carbohydrate which is not easily oxidized by an oxidizing agent in an aqueous solution that is generally weak. The main characteristic of these sugars is they do not make any compound that contains an aldehyde group.
- Sucrose is a nonreducing sugar because it does not have a hemiacetal group or Hemiketal group. Hence, it is stable in water.
- For recognizing that the sugar which is given Is reducing or non- reducing, we generally use the Benedict test. Benedict is a solution when added to the sugar, the color of sugar will not change. This shows that given sugar is non reducing sugar. If the given sugar color changes then it is considered as reducing sugar, like glucose, fructose, maltose.

So, the correct answer is, "Sucrose".

Additional information: In plants, sucrose is very important because it helps in the transportation of carbon in them. Sucrose is easily dissolved in water. Plant cells transport sucrose in phloem and vascular tissue, which is mainly created to carry sugar. In the cells where it is generated, it reaches to the intercellular spaces in the leaf and comes to the vascular bundle where special cells pump it in the phloem.
- To stop the solidifying of sugar, xylem, or vascular tube add little water. Then sucrose moves down the phloem to reach the stem and roots(generally don't have chloroplast), and is dependent on leaves for energy.
- Sucrose gets absorbed in these cells and their enzymes break it into different components. Now, it reaches within mitochondria and undergoes the Kreb cycle to generate ATP for energy.ATP is used in many reactions that cells need for the maintenance of stem and roots.

Note:
- Life on earth totally depends on Sucrose and also to many other carbohydrates as it is the first thing that is taken out from plants on a large scale to make white sugars.
- Sugarcane and sugar beet contain sucrose.