[Biology Class Notes] on Difference Between Globular and Fibrous Protein Pdf

Protein is present abundantly in our body. They are compounds formed by amino acids. These amino acids are attached to one another in a long chain-like structure to form a protein. Proteins are polymers or macromolecules made up of smaller structural units. Most functions in our body occur due to the presence of protein. Different types of protein help in the smooth functioning of our body. 

Processes like DNA replication, transporting molecules, providing structural balance to cells and organs, response to stimuli, and metabolic reactions are supported by proteins. Proteins are classified on the basis of the sequence of amino acids, and upon the basis of structure and function. The four different levels of a protein structure are- primary, secondary, tertiary, and quaternary structure. On the basis of function, proteins can be classified as fibrous protein, globular protein, and membrane protein. We will discuss the difference between fibrous and globular proteins and the different types of protein.

Types of Proteins

Protein is present in our hairs, nails, muscles, and in the haemoglobin present in our red blood cells. Depending upon the functions of protein we differentiate protein into three types- globular, fibrous, and membrane proteins. These proteins help in the normal functioning of the body. Let us discuss these three types of proteins in detail.

Globular proteins have a spherical structure. These are one of the most abundant types of proteins. Globular proteins help in bodily functions. These proteins are mostly soluble in water and form colloids. They act as enzymes, messengers, transporters, regulators, and sometimes also as structural protein. Haemoglobin is a common globular protein.

Fibrous proteins are made up of sheet-like filamentous structures. Fibrous proteins have low solubility in water. These types of protein provide protection and function in the structural role by forming connective tissues, tendons, and muscle fibres. Fibrous proteins are made up of regular amino acid sequences. The most common form of fibrous protein is collagen.

Membrane proteins as the name suggests are commonly found and are present in the membranes. They interact with biological membranes and therefore are the target of medicinal drugs. These help in providing receptor signals between the internal and external environments of the cell. Also, they help in transporting molecules and allow interaction between molecules. Types of membrane proteins include integral membrane protein and peripheral membrane protein.

Common Proteins and Their Uses

Globular Proteins 

1. Haemoglobin: It is the red colour pigment found in our red blood cells. Haemoglobin is the reason why our blood is red in colour. Its main function is to store and transport oxygen to different parts of the body. The level of haemoglobin should always be maintained in a body as lower amounts of haemoglobin can lead to lower amounts of oxygen and higher amounts of haemoglobin can lead to thickening of the blood which can further lead to heart attack, strokes. 

2. Insulin: Insulin is formed in our pancreas which regulates the level of sugar in our body. It allows glucose to enter our body so that the cells can provide energy. 

Fibrous Proteins

1. Collagen- It is a type of protein that is most abundant in humans (30%). It is made up of amino acids which are further made up of carbon, hydrogen, and oxygen. It gives strength to our various body parts and also protects them. It is a major part of human skin and nails.

2. Keratin- It is a type of fibrous protein which is present in our hair, nails, and skin. It can also be found in most of the organs inside our body. 

What is the Difference between Fibrous Protein and Globular Protein?

Globular protein and fibrous protein are different types of protein that are essential in the proper functioning of a human body. While globular helps in a variety of functions, fibrous proteins are involved in providing structural stability to the organism. Proteins are made up of amino acid strands.   

Globular protein and fibrous protein have some differences. These are due to changes in the structure of the protein and the sequence of amino acids. The differences between fibrous protein and globular protein are given below:

 

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