Problem 147 - Objective Biology for NEET

Question

Assertion: In human body 'collagen' is the most abundant protein. Reason: Scleroproteins occurs in hard parts of animals body for providing support and protection.

Step-by-Step Solution

Answer

The given assertion 'In human body 'collagen' is the most abundant protein' is correct, and the reasoning 'Scleroproteins occur in hard parts of animals body for providing support and protection' is also correct and directly supports the assertion. Therefore, both the statement and the reason given are correct.

Step 1: Identify the proteins in the human body

Collagen is indeed one of the proteins found in the human body. There are several types of proteins present, but it's important to notice that collagen is considered one of the most abundant ones.

Step 2: Understand the role of scleroproteins

Scleroproteins are structural proteins that occur in cells and tissues. They do provide support and protection in animal bodies, including humans. Examples of scleroproteins include keratin, collagen, and elastin.

Step 3: Associate Collagen and Scleroproteins

Upon knowing that collagen is indeed a protein and that it belongs to the group of scleroproteins which give structure and protection to animals’ bodies, it can be concluded that the reason given is supportive of the assertion.

Key Concepts

Scleroproteins

Scleroproteins, also known as fibrous proteins, are essential building blocks in the bodies of animals and humans. They are known for their fibrous and elongated structures, which make them resilient and sturdy. This unique structure enables scleroproteins to provide the necessary toughness and resistance required for maintaining the structural integrity of tissues.

One of the primary roles of scleroproteins is to offer support and protection. They are found in various parts of the body, often in the "hard" or supportive tissues, such as tendons, bones, and skin.

• Common characteristics include insolubility in water, which enhances their functionality in providing rigidity and strength.
• Examples of scleroproteins in humans include collagen, keratin, and elastin.

Their capacity to form networks and fibers makes them fundamental to the body's architecture.

Human body proteins

Proteins are vital macromolecules present throughout the human body. They perform a diverse range of functions that are essential for life. Proteins in the human body are classified into different types based on their functions and structures.

The most abundant groups include:

• Structural proteins, such as collagen, that maintain the form and support of cells and tissues.
• Enzymes, which facilitate biochemical reactions.
• Transport proteins, like hemoglobin that carries oxygen.

Each protein is made up of amino acids and is designed to perform a specific job, which shows the complexity and versatility of proteins in supporting life and health.

Structural proteins

Structural proteins are indispensable for the framework and shape of cells and tissues. They are involved in creating the infrastructure that maintains the physical integrity of the body.

Structural proteins are particularly crucial in forming tissues that have a load-bearing or protective function. This includes maintaining the elasticity and tensile strength required for daily activities and body movement.
Examples of structural proteins include:

• Collagen: The most abundant protein in the human body, essential for skin, bones, and connective tissues.
• Keratin: Vital for hair, nails, and the outer layer of skin, providing barrier protection and resilience.
• Elastin: Allows tissues to resume their shape after stretching or contracting, found in vessels and lungs.

These proteins are responsible for the body's structural composition and are crucial for maintaining overall body strength and flexibility.

Keratin

Keratin is a type of scleroprotein and is one of the key structural proteins in the human body. It is best known for its role in forming the epidermis, hair, and nails, where it provides durability and protection.

Keratin is highly resistant to wear and tear, making it effective in protecting sensitive tissues beneath the skin.

• It is insoluble in water and in most organic solvents.
• Keratin found in hair and nails differs slightly in structure, allowing it to accommodate different physical properties.

The strength and resilience of keratin make it a crucial part of the body's defense against environmental damage.

Elastin

Elastin is another important scleroprotein that provides elasticity and resilience to various tissues in the body. Its primary function is to allow tissues to stretch and return to their original shape.

Elastin is essential in areas of the body that require both flexibility and strength. This includes:

• Blood vessels: Elastin helps maintain blood pressure by allowing vessels to stretch and relax.
• Lungs: Facilitates breathing by enabling lung tissues to expand and contract.
• Skin: Provides elasticity, aiding in resistance to distension and allowing skin to return to normal after being pinched or poked.

Without elastin, tissues would lose their ability to handle physiological stresses and strains, showcasing its importance in maintaining balance and function across various systems.