Difference Between Gene and Protein

Gene vs Protein
 

Though Gene and Protein are closely related, there are definite differences between their function and physiology. Gene and Protein are two very closely related biomaterials in the body system. The gene function is expressed in the form of protein. This makes the closest link between genes and proteins. Both gene and protein are vital compound in life and help to build the relationship between genotype and phenotype in genetics. This molecular relationship is explained by the one-gene/one-polypeptide hypothesis. Francis Crick was the first person to describe the information flow in cells, which leads the conversion of genotype to phenotype. Single direction information flow in cells is as follows.

DNA (gene) → RNA → protein

The DNA-to-RNA step is known as transcription, while the RNA-to-protein is called translation. The main focus of this article is the difference between gene and protein, while the function and physiology of gene and protein too will be considered.

What is Gene?

A gene is considered as the basic unit of genetic information. It is located on a chromosome at a specific genetic locus. The genetic information located in the specific locus is usually transcribed into a single RNA molecule, which eventually is coded for a particular protein. These genes are called protein-coding genes. Not all RNA transcribed from genes are translated into proteins. These genes are called non-coding genes. The study of genes is called genetics. In eukaryotes, chromosome pairs are arranged as homologous pairs. Different forms of the same gene located at the same position or locus are known as alleles. Eukaryotic genes are more complex than prokaryotic genes and contain the intervening sequences called introns. The other regulatory sections found in genes are called exons, which make up the mRNA. In human, the smallest protein-encoding gene consists about 500 nucleotides with no introns and encodes a histone protein. The largest protein-encoding gene in human contains about 2.5 million nucleotides and encodes the protein called dystrophin.

Difference Between Gene and Protein

Bacterial DNA transcribed into mRNA and then translated into protein

What is Protein?

Proteins are the most diverse biological macromolecules with various functions, including enzyme catalysis, defense, transport, support, motion, regulation, and storage. Protein structure is determined by a particular gene in the body. Functional and structural unit of proteins is amino acid. As the name implies, amino acid consists of an amino group (-NH2) and an acidic carboxyl group (-COOH). There are 20 different amino acids arranged in different sequences through peptide bonds, to produce all the proteins in the body. A chain of amino acids connected by peptide bonds is called a polypeptide.

The structure or shape of a protein determines its function. The amino acid sequence is determined by the protein’s primary structure. The presence of several peptide groups within a protein can lead the formation of hydrogen bonds between nearby amino acids. This can alter the structure and determine the secondary structure of a protein. The tertiary structure; final 3-D shape of a protein determines by the folds and links in the protein. Quaternary structure of a protein is found only in the protein with multiple polypeptides.

What is the difference between Gene and Protein?

• Genes function is expressed through protein (gene determines the primary structure of a particular protein in the body).

• Gene is made up of DNA, whereas protein is made up of amino acids.

• Genes carry the genotype, whereas proteins express the phenotypes.

• The main function of a gene is to carry heredity information, whereas main functions of protein include enzyme catalysis, defense, transport, support, motion, regulation, and storage.

 

Images Courtesy:

  1. Bacterial DNA transcribed into mRNA and then translated into protein by Miluk2014 (CC BY-SA 3.0)