Central Dogma of Molecular Biology

A Central Dogma describes how DNA is converted to RNA and then into Proteins in Molecular Biology. A genomic process refers to the conversion of DNA information into a functional product.

RNA serves as a messenger to carry information through the Ribosomes as DNA provides instructions for making Proteins.

The Central Dogma is the biological process that transfers Genetic information from DNA to RNA, and then into Proteins.

What is the Central Dogma?

A Central Dogma is an explanation of the flow of Genetic information in a cell, including the replication of the DNA, the transcription of the RNA, and the translation of the RNA to create the Proteins.

It is possible to understand the concept of interaction through the framework. For example, biopolymers are common. Biopolymers are primarily composed of Proteins, RNA, and DNA, which can further be divided into general and unknown transfers.

In the laboratory, special transfers are made in exceptional cases. Cells are generally transferred by general means. Information is constantly flowing through transcription and translation in the human body. It is believed that unknown transfers never occur.

As a result, two new strands of DNA are created, one strand from the parent DNA and one from the newly synthesized DNA. This is called semiconservative DNA replication.

Steps of the Central Dogma

The central dogma takes place in two tages:

1. Transcription

The enzyme RNA Polymerase transfers information from one strand of DNA to another strand of RNA during transcription. Three parts of the DNA strand are involved in this process: the promoter, the structural gene, and the terminator.

DNA strands that synthesize RNA are called template strands, and DNA strands that Code for RNA are called coding strands. RNA polymerases that are DNA-dependent bind to the promoter and catalyze the 3' to 5' directions of polymerization.

The newly synthesized RNA strand is released from the terminator sequence as it approaches the terminator. RNA strands released after transcription undergo further modifications post-transcriptionally.

2. Translation

Proteins are enCoded by RNA by a process called translation. Translation involves energy and is an active process. The energy comes from the charged tRNA Molecules.

The translation process is initiated by ribosomes. Ribosomes are made up of two subunits, one larger and one smaller. As a result, the larger subunit consists of two tRNA Molecules positioned together so that enough energy can be expended to form a peptide bond. 

The mRNA enters the smaller subunit and is then held by the tRNA Molecules present in the larger subunit that are complementary to the codon. In this way, two codons are held together by two tRNA Molecules placed close together and a peptide bond is formed between them. This process results in long polypeptide chains of amino acids.

Genetic Code

Proteins are manufactured from RNA and their Genetic Code contains information about them. In general, three nucleotides and four nitrogenous bases collectively Code for an amino acid, forming a triplet codon. As a result, there are 64 amino acids possible, including 4 x 4 x 4 amino acids. There are 20 amino acids found naturally.

As a result, the Genetic Code deteriorates. Due to the characteristics of the Genetic Code, some amino acids are enCoded by more than one codon at a time, causing the amino acid to degenerate. There is only one codon for each amino acid and the Code is universal regardless of the organism.

In total, there are 64 codons, of which three are stop codons that end transcription and one is an initiator codon, i.e. AUG, which Codes for methionine.