Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Biomolecules

Question:

Which among the following groups consist of all polysaccharides ?

Options:

Maltose ,lactose , glucose

Fructose , sucrose , maltose

Starch ,cellulose and Glycogen

Glycogen ,sucrose , glucose

Correct Answer:

Starch ,cellulose and Glycogen

Explanation:

The correct answer is Option (3) –Starch ,cellulose and Glycogen

Polysaccharides are long chains of sugars. They are threads (literally a cotton thread) containing different monosaccharides as building blocks. For example, cellulose is a polymeric polysaccharide consisting of only one type of monosaccharide i.e., glucose. Cellulose is a homopolymer. Starch is a variant of this but present as a store house of energy in plant tissues. Animals have another variant called glycogen. Inulin is a polymer of fructose. In a polysaccharide chain (say glycogen), the right end is called the reducing end and the left end is called the non-reducing end. It has branches as shown in the form of a cartoon . Starch forms helical secondary structures.

Plant cell walls are made of cellulose. Paper made from plant pulp and cotton fibre is cellulosic. There are more complex polysaccharides in nature. They have as building blocks, amino-sugars and chemically modified sugars (e.g., glucosamine, N-acetyl galactosamine, etc.). Exoskeletons of arthropods, for example, have a complex polysaccharide called chitin. These complex polysaccharides are mostly homopolymers .