Problem 101 - A Complete Resource Book in Chemistry for JEE Main

Question

Which of the following are biopolymers? (a) Leather (b) Nucleic acids (c) Orlon (d) Bakelite

Step-by-Step Solution

Answer

Nucleic acids and leather (due to collagen) are biopolymers.

Step 1: Understand the Definition of Biopolymers

Biopolymers are polymers that are naturally occurring and produced by living organisms. They are composed of large molecules made by the joining together of smaller units called monomers. Examples include proteins, nucleic acids, and polysaccharides.

Step 2: Analyze Each Option

We will analyze each option to determine if it is a biopolymer. Begin with option (a), Leather: Leather is a material created from animal skin, consisting mostly of collagen, a protein. Proteins are biopolymers composed of amino acids. Therefore, leather is associated with biopolymers.

Step 3: Evaluate Nucleic Acids

Option (b), nucleic acids, such as DNA and RNA, are essential biopolymers found in all living cells. They are composed of monomers called nucleotides, making them biopolymers.

Step 4: Investigate Orlon

Option (c), Orlon, is a synthetic acrylic fiber. It is made from polyacrylonitrile, a synthetic polymer and not a naturally occurring one. Therefore, Orlon is not a biopolymer.

Step 5: Examine Bakelite

Option (d), Bakelite, is a synthetic plastic, known as phenol-formaldehyde resin. It is one of the earliest synthetic polymers and does not occur naturally, therefore it is not a biopolymer.

Step 6: Conclusion

Based on the analysis, options (b) nucleic acids and part of (a) leather (due to its collagen content) are biopolymers, while (c) Orlon and (d) Bakelite are not.

Key Concepts

Nucleic Acids

Nucleic acids are vital biopolymers found in every form of life, forming the core of biological information systems. They include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), both of which are crucial for storing and transmitting genetic information. Nucleic acids are made of smaller units called nucleotides. Each nucleotide consists of three components:

• A sugar molecule (deoxyribose in DNA and ribose in RNA)
• A phosphate group
• A nitrogenous base (adenine, guanine, cytosine, and either thymine in DNA or uracil in RNA)

These components form long chains, with the sequence of nitrogenous bases encoding genetic instructions for processes such as cell growth and protein synthesis.
Nucleic acids are pivotal for life's continuity, facilitating the cell's ability to replicate and pass genetic material to offspring. Their unique properties have garnered applications beyond biology, including genetic engineering and forensics.

Proteins

Proteins are remarkable biopolymers composed of amino acid chains, contributing to virtually every biological function. Amino acids are linked by peptide bonds, forming complex structures with unique functions depending on their sequence and folding pattern.
Proteins serve numerous roles, including:

• Structural support (e.g., collagen in connective tissues)
• Enzyme catalysis (accelerating biochemical reactions)
• Transport and storage (e.g., hemoglobin carrying oxygen)
• Cell signaling and immune response

Their diversity arises from 20 different amino acids, each with distinct properties, allowing proteins to take on myriad shapes and functions. This structural variation is critical for the specific interactions and tasks required within living organisms.
In addition to natural structures like leather, proteins are engineered for pharmaceuticals and industrial processes, showcasing their versatility beyond biological systems.

Synthetic Polymers

Synthetic polymers, unlike biopolymers, are human-made from chemical processes and serve numerous commercial and industrial applications. Unlike the naturally occurring monomers in biopolymers, synthetic polymers, such as Orlon and Bakelite, are crafted from artificial monomers. **Characteristics of synthetic polymers include:**

• Durability and resistance to environmental factors
• Flexibility in design for varied applications, from textiles to electronics
• Cost-effectiveness, given their mass production potential

Orlon, known for its wool-like qualities, is used in clothing, offering affordability and durability. Bakelite, a thermosetting plastic, revolutionized the manufacture of electrical insulators and consumer goods due to its heat-resistant properties. However, their synthetic nature comes with environmental concerns, as they are typically non-biodegradable. This creates waste management challenges, prompting the development of biodegradable alternatives to address both the utility and environmental impacts effectively.