Biological Functions Of Proteins: Roles, Function, Importance

Large biomolecules and macromolecules known as proteins comprise one or more extended chains of amino acid residues. Among the many tasks that proteins carry out in living things include catalyzing metabolic processes, replicating DNA, reacting to stimuli, giving cells and organisms shape, and moving chemicals from one place to another. The primary way that proteins differ from one another is in the order of their amino acids, which is determined by the nucleotide sequence of their genes and often causes a protein to fold into a certain 3D shape that controls its function.

A polypeptide is an ordered sequence of amino acid residues. At least one long polypeptide is present in every protein. Less than 20–30 residue polypeptides are frequently referred to as peptides and are seldom thought of as proteins.

Structure Of Protein

Muscles, bones, skin, hair, and almost all other human organs and tissues include protein. It serves as the foundation for enzymes and fuels numerous chemical reactions and hemoglobin, which carries oxygen in your blood.

The twenty-plus fundamental building blocks of protein are known as amino acids. Our bodies manufacture amino acids in one of two ways since we cannot store them: either from scratch or by altering other amino acids. Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine are some of the necessary amino acids that must be absorbed from the diet.

Functions Of Protein

Proteins are essential for carrying out complicated activities as well as for the synthesis and renewal of DNA. Proteins are called enzymes to help break down food.

Numerous hormones that aid in maintaining the balance of the body's constituent parts are connected to the production of proteins. Cells interact with one another and with the outside environment through surface receptors. Proteins make up these receptors.

The immune system employs antibodies, proteins found in the body, to mend and heal the body after foreign infections have been introduced. Proteins that enable communication between cells and organs.

• Digestive Enzymes

The enzymes that aid in digestion are specific proteins. To put it another way, they break down nutrients into their essential monomeric components. The digestive enzymes pepsin and amylase are two examples.

• Structural Proteins

Proteins that are essential because they make up parts of some structures. Tubulin and keratin are two examples.

• Hormonal Functions

Hormones are crucial for controlling how the body works. One such instance is insulin.

• Transportation

Proteins are essential for moving materials throughout the body. Haemoglobin is one such instance of such a protein.

• Defence and Protection

Proteins also play an essential role in the immune system, which defends the body against infections. An illustration of one such protein is an immunoglobulin.

• Storage Functions

Albumin and egg white are two proteins feeding the developing embryo.

The Structure Of Protein

To create protein structures, amino acids condense and form peptide bonds. A peptide bond (-CO-NH) is created between the amine group of one molecule and the carboxyl group of the neighboring molecule, which is followed by the elimination of a water molecule. If not, this connection is an amide one. A polypeptide chain is created when peptide bonds are established between more than ten amino acids. A protein is produced when a polypeptide chain has a mass of more than 10,000 u and more than 100 amino acids.

Different Types Of Structure Of Proteins

• Primary Structure

The arrangement of amino acids that make up a polypeptide chain is known as the fundamental structure. Twenty different amino acids make up proteins. A protein's fundamental sequence is the arrangement of its amino acids.

• Secondary Structure

The secondary structure of a protein refers to the regular, recurring folding patterns that make up its backbone. The beta-sheet and the alpha-helix are the two most prevalent folding patterns.

One of the most common methods for a polypeptide chain to produce all available hydrogen bonds is the helix, which involves twisting into a right-handed screw and hydrogen-bonding each amino acid residue -NH group to the -CO of the subsequent helix turn. As they twisted, the polypeptide chains created a right-handed screw. The polypeptide chains are positioned adjacent and joined by H-bonds like a pleated sheet. This structure, which is held together by intermolecular hydrogen bonds, is formed by stretching each peptide chain to almost its maximum extent. The name "pleated sheet" comes from how the structure mimics the folded pleats of drapery.

• Tertiary Structure

The tertiary structure is the whole polypeptide chain folded into a precise 3D form. A compact, spherical tertiary structure is typical of enzymes.

• Quaternary Structure

Polypeptide chains make up a large portion of proteins. The arrangement of the different subunits to create the overall structure is described by the quaternary structure of a protein.

Biological Role of Protein

Proteins are the fundamental components of life and give living things the structural support they need to develop and flourish. Actually, "protein" comes from the Greek adjective proteos, which means "the most significant." Each protein comprises a lengthy chain of amino acids linked together by peptides. The human body alone may express hundreds of thousands of distinct proteins, although these chains only include 20 different amino acids.

Would you want to learn more about how proteins and biological function are related? Continue reading as we highlight some essential functions protein performs in biological systems, from mending tissue to catalysing metabolic events.