Problem 17 - Objective Biology for NEET

Question

The stored form of glucose in plant is (a) Inulin (b) Sucrose (c) Starch (d) Glycogen

Step-by-Step Solution

Answer

The stored form of glucose in plants is (c) Starch.

Step 1: Understanding the problem

The problem provides four potential forms of glucose storage in plants: Inulin, Sucrose, Starch, and Glycogen. The task is to pick the correct answer.

Step 2: Recall biochemical facts

It is a known fact in biochemistry that plants store glucose in the form of polymers, which can be further broken down into glucose units whenever energy is needed by the plant. Starch, being a polysaccharide, serves this purpose in the plant cells.

Step 3: Identify the right choice

As the analysis has shown, the forms of glucose storage in plants is Starch. Therefore, the correct answer is option (c) Starch.

Key Concepts

Biochemistry

Biochemistry is the study of chemical processes that occur within living organisms. When it comes to plants, biochemistry explores how plants convert light energy into chemical energy through photosynthesis. This energy is primarily stored in the form of glucose. Plants utilize sunlight, water, and carbon dioxide to produce glucose, a simple sugar that serves as an immediate energy source. However, plants often need to store this glucose for later use. Consequently, they engage in a few biochemical pathways to polymerize glucose into larger storage molecules. Understanding these biochemical pathways helps scientists and students understand how plants adapt to their environment and manage energy resources efficiently.

Plant Polysaccharides

Polysaccharides are large molecules made by combining several sugar molecules. In plants, they play a crucial role in storing energy and providing structural support. The term polysaccharide comes from 'poly', meaning many, and 'saccharide', meaning sugar. Starch, a primary storage polysaccharide, is composed of two types of molecules: amylose and amylopectin.

• Amylose is linear, allowing it to pack tightly and form compact structures ideal for storage.
• Amylopectin has a branched structure, making it more accessible for enzymes to break down rapidly when energy is needed.

Starch storage enables plants to have a reserve of energy in leaves, seeds, and roots. Cellulose, another polysaccharide, forms the structural framework of plant cell walls. Unlike starch, cellulose's rigid fibers provide strength and support, showcasing the versatility of polysaccharides in plant life.

Glucose Polymers

Glucose polymers consist of repeating glucose units linked together. In plants, the polymerization process results in the formation of starch, a crucial storage component. Unlike simple glucose molecules, these polymers are not readily soluble in water, making them ideal for storage. When a plant needs energy, it can break down these glucose polymers back into glucose units through enzymes such as amylase. This breakdown process is vital during periods of low sunlight or when the plant requires additional energy for growth or reproduction. Furthermore, glucose polymers are not only essential for energy storage but also play critical roles in seed germination, where stored starch is converted to glucose needed for initial growth phases before the plant can photosynthesize efficiently.