The vital sequence of different processes that transfers the genetic code from DNA via mRNA to finally form the functional product (finished proteins) together forms the central dogma of modern molecular biology. Thus, the genetic code is the basis of the central dogma of molecular biology. Central dogma is nothing but the flow of genetic information in all living cells including human cells from DNA to RNA to proteins.
The central dogma
There are three classes of sequential biopolymers that encode information: DNA, RNA, and protein. The central dogma of microbiology describes the ways in which information flows among these three classes: DNA replication (DNA to DNA), transcription …show more content…
This DNA or the genetic material is transferred from parents to offspring. Moreover, it has the potential to influence various traits or characteristics such as hair color, eye color, etc. of the offspring. Now the question arises, how does a particular DNA sequence can influence an organism’s features? For example how a sequence of nucleotide in DNA can determine what color of eyes of a children will inherit from its parents. Consider Mendel’s pea plants, how patterns of A’s, T’s, G’s, and C’s present in the nucleotide sequence of DNA have helped in the determination of the color of the flowers?
The answer to this lies in the genetic code and the central dogma of molecular biology.
Genes Act as the Instruction for the Final Functional Product
Strands of DNA may seem like a quite monotonous string of nucleotides. On contrary, it is actually a series of functional units present together. These functional units are called as gene and genes act as the instructions for the formation of the final product. This final product which is mostly a protein or polypeptide is an essential component to perform particular functions and processes needed in the …show more content…
This directional flow of information is nothing but central dogma of molecular biology. There is non-protein coding genes present which undergo transcription to produce RNA. However, this type of RNA will not be translated into polypeptides. Both the type of gene when undergoing the process of converting DNA to a functional product is known as gene expression. Therefore, gene expression is the process of conversion of DNA instructions into the final product.
Genetic Code
In the translation process, the mRNA nucleotide sequence specifies the amino acid sequence. This means that the nucleotides are mRNA is read in a group of three or triplets. The triplets are the codons. There are 64 codons out of which only 61 codons specify amino acids and rest three are stop codons.
Now, how to distinguish what codon will specify what amino acid? This is determined by start codon that will indicate the amino acid. This again depends on another concept known as the reading frame. The start codon signals the start of the translation process. Generally, the start codon specifies the methionine amino acid. Hence, mostly polypeptides start with an amino