Central Dogma of Life and Its Significance

In this central dogma of life and its significance post we have briefly explained about the central dogma of life, replication, transcription, and translation. Read on to learn more about the central dogma of life!!

The Central Dogma of Life

Life of an organism required coordinated function of different organs or tissues. Even in the unicellular system, cellular processes are controlled by a series of molecular events, mostly controlled by signal transduction. Signal transduction is a series of phosphorylation events performed by protein kinases. In addition, co-ordination between different organs through messenger molecules, which are also, is proteinous in nature. 

In addition, the phenotypic changes (skin color, feather and pattern) in an organism are required for adaptation and biological demands such as selecting suitable life partner. Most of these examples are associated with the synthesis of suitable protein factor in a time and context dependent manner. The protein is made up of amino acids and every protein has unique amino acid arranged in a specific sequence. 

The information to synthesize proteins with unique amino acid sequence is provided by the nucleic acid present within the nucleus. In a preset sequence, DNA present in the nucleus give rise to the specific RNA sequence and that in turn guide the cellular machinery to synthesize protein. 

Scientist considered this as the fundamental event to run the life and considered as “the central dogma of life”.  In another word Francis in his communication to jounrla Nature states “The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred back from protein to either protein or nucleic acid”.

Central Dogma of Life

The Central Dogma of Life: Sequence of Information Flow in Biological System

Central Dogma of Life and Its Significance

The central dogma of life is the basis of life on earth and required to control the biological processes. Following this hierarchical flow of information from DNA to protein allows nucleus to control all biological activities in a cell. Under normal conditions, the flow of information sequence-to-sequence requires 3 processes.

Central Dogma of Life

The Central Dogma of Life: Flow of Information sequence-to sequence in Biological System

Replication

Genomic content in an organism needs to be duplicated during S phase of cell-cycle. Duplication of DNA is done by replication utilizing the sequence information of parent DNA. The enzyme used for this purpose is DNA dependent DNA polymerase.

Transcription

The DNA is present in nucleus whereas the protein synthesis machinery is present in cytosol. Hence the information present in DNA is used to synthesize RNA which has ability to transport outside the nucleus to participate into protein synthesis. Synthesis of RNA from DNA is done by transcription utilizing the sequence information of DNA. The enzyme used for this purpose is DNA dependent RNA polymerase.

Translation

The RNA present in cytosol is utilized by translation machinery to synthesize protein in a sequence dependent manner through a process known as translation.

The Central Dogma of Life: Flow of Information under normal and special circumstances  

Under specific conditions, biological system does not follow the usual pathways to replay the information. Few of the special circumstances and underlying events are given in the Table.

Reverse Transcription:  In most of the organism, genomic content is present in the form of DNA but in few organisms such as virus, RNA is present as genomic content and in these cases, RNA needs to be converted into DNA and replicate using the host replication machinery. It is done by reverse transcription utilizing the sequence information of parent RNA. The enzyme used for this purpose is RNA dependent DNA polymerase.

RNA replication:  In most of the organism, genomic content is present in the form of DNA but in few organisms such as virus, RNA is present as genomic content and duplication of RNA is done by replication utilizing the sequence information of parent RNA. The enzyme used for this purpose is RNA dependent RNA polymerase.

DNA directly to Protein: Under in-vitro cell free system, it is possible to translate DNA directly into the protein in the presence of ribosome. It is not precisely controlled and it is not known whether it synthesizes the protein in a sequence dependent manner.

Protein to protein: These are considered as infectious protein which replicates to form identical copies on themselves. These proteins are known as prions. Although it represent the transfer of information but it is not the usual pathway and considered to be the exception of central dogma.

Central Dogma of Life

The Central Dogma of Life: Flow of Information under special circumstances in Biological System. Special processes are colored in green

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