Story of Gene

Image credit: stergiog.blogspot.com

History

The story of genetics begins when Friedrich miescher isolated the substance from the cell and termed it as “nuclein” in 1869. He believed that the nuclei is an organelle which is responsible for the inheritance of characteristics. Later on his student Richard Altmann named it “nucleic acid”. The term gene is coined by wilhem johannsen in 1909. 

Function

A gene is a functional unit of heredity. Characters are inherited from one generation to other in the form of a gene in all organism on earth. One specific gene is responsible for the inheritance of one specific character. It is made up of DNA, actually, it is the part of DNA which code for particular protein. It is important to understand that the gene itself is a DNA sequence. For more detail on DNA click here. 

20,000 to 25,000 genes are identified to date, thanks to the team of the human genome project. Gene codes for protein. Proteins are functionally important for all biological activity. Generally, people think that genes translate into proteins than how the other biological molecules are created.

Other important biological molecules like carbohydrates and lipids are synthesized in our body. Is it possible for any biological reaction to complete without the help of an enzyme? These enzymes are actually proteins. Receptors, chaperones, hormones,  cell surface molecules, immunoglobulins etc are all the different forms of protein which are encoded by genes.

Structure

It is a part of DNA hence it is basically a long chain of A, T, G and C. A double-stranded functional portion of DNA has different sequences which are recognized by enzymes during transcription and translation.

The image represents the general structure of Gene with a promoter, exon and intron

Promoter, introns and exons are the major part of a gene. The promoter is a sequence located at the beginning of a gene. These promoter sequences are recognized during the gene expression by specific enzymes. Introns and exons are located tendomly on genes. Numbers of Intron and exon are varies for different genes.

Exons are coding region and introns are interspersed between two exons and are non coding sequences. When DNA is under go for transcription introns are spliced out, the remaining exonic sequences are called as “pre mRNA” which later turns into mature RNA. 

Articles written and reviewed by- Tushar Chauhan

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Story of DNA

Story of Protein

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