Problem 109 - A Complete Resource Book in Chemistry for JEE Main

Question

Match the following $$ \begin{array}{ll} \hline \text { Column-I } & \text { Column-II } \\ \hline \text { (a) Starch } & \text { (p) Polymer of amino acid } \\ \text { (b) Nylon - } 6 & \text { (q) Polymer of } \alpha-D \text {-Glucose } \\\ \text { (c) Protein } & \text { (r) Polyamide } \\ \text { (d) Natural rubber } & \text { (s) Isoprene } \\ & \text { (t) Caprolactum } \\ \hline \end{array} $$

Step-by-Step Solution

Answer

(a) - (q), (b) - (t), (c) - (p), (d) - (s)

Step 1: Understanding Starch

Starch is a carbohydrate consisting of a large number of glucose units joined by glycosidic bonds. It is a polysaccharide composed of alpha-D-glucose units. Therefore, starch should be matched with Column-II option (q).

Step 2: Identifying Nylon - 6

Nylon-6 is a synthetic polymer known as a polyamide. It is made from the monomer caprolactam. Therefore, Nylon-6 should be matched with Column-II option (t).

Step 3: Analyzing Protein

Proteins are large biomolecules consisting of one or more long chains of amino acid residues. They are polymers of amino acids. Therefore, protein should be matched with Column-II option (p).

Step 4: Recognizing Natural Rubber

Natural rubber is primarily composed of a polymer of isoprene. Therefore, natural rubber should be matched with Column-II option (s).

Key Concepts

Starch

Starch is a carbohydrate that plays a crucial role in the diet of many organisms as a primary source of energy. It is a polysaccharide composed of many glucose units linked together via glycosidic bonds, specifically in the form of alpha-D-glucose. These glucose molecules are structured in such a way that they can be easily broken down during digestion, making starch an accessible form of energy.
Starch is found naturally in foods such as potatoes, rice, and corn. In plants, it serves as a way to store energy, and is synthesized through photosynthesis. To human and animal bodies, it provides the energy needed to perform daily activities.

• Key Feature: Composed of alpha-D-glucose units.
• Main Function: Serves as an energy reserve in plants.
• Common Sources: Potatoes, corn, and other staple foods.

Its structure is primarily made up of two types of molecules: amylopectin and amylose. Both play a distinct role in the physical properties of starch, such as its tendency to gel or thicken when heated in water.

Nylon-6

Nylon-6 is a type of synthetic polymer known as a polyamide, which is renowned for its strength, elasticity, and resistance to wear and tear. This makes it a highly valuable material in various industrial applications, including textiles, automotive components, and even in medical devices. It is made from the monomer caprolactam.
The production of Nylon-6 involves the polymerization of caprolactam in a process that forms long chains of repeating amide groups (-CONH-). These chains provide the strong intermolecular forces that give Nylon-6 its durable characteristics.

• Composition: Made from the monomer caprolactam.
• Key Characteristics: Strength and elasticity.
• Applications: Textiles, automotive parts, medical devices.

Nylon-6 is often used in clothing, such as tights and swimming gear, due to its stretchable yet sturdy nature. Its versatility and robustness make it an essential component in the manufacturing of durable goods.

Proteins

Proteins are vital macromolecules involved in nearly every biological process within organisms. They are polymers made up of amino acids linked together in a specific sequence dictated by genes. The sequence of these amino acids determines a protein's structure and function.
Proteins serve a wide range of functions, from structural support in tissues, such as skin and muscle, to acting as enzymes that facilitate biochemical reactions. They are also crucial in immune response and signaling processes.

• Foundational Units: Composed of one or more long chains of amino acids.
• Functions: Include catalysis, structural support, signaling, and immune response.
• Examples: Enzymes, antibodies, collagen.

The diversity of proteins is incredible, with each type of protein having a unique role tailored by the precise sequence and folding of its amino acids. Understanding proteins is fundamental to grasping how living organisms function and interact with their environment.

Natural Rubber

Natural rubber is a fascinating polymer that has important industrial applications due to its elasticity and resilience. It is primarily composed of the polymer polyisoprene, which originates from the sap of rubber trees (Hevea brasiliensis). These trees produce latex, which is harvested and processed into rubber.
Polyisoprene's molecular structure gives natural rubber its unique properties, such as being stretchable, stretchy, and capable of returning to its original shape after twisting or pulling. This makes it an ideal material for products that require flexibility and durability, such as tires, elastic bands, and waterproof clothing.

• Main Constituent: Polymer of isoprene.
• Key Properties: Elasticity, durability, and flexibility.
• Primary Uses: Tires, footwear, and elastic materials.

Globally, natural rubber is essential to many industries, particularly automotive and manufacturing, where its ability to absorb impacts and provide grip is highly valued. It is a prime example of how a natural product can be integral to modern technology.