The purpose of this paper is the review of the major principles and rules of the Central Dogma of molecular biology. The Central Dogma was first introduced in 1958, and it is meant to explain the universal rules of genetic information realization. The Dogma describes the basic principles of genetic information transfer: transcription and translation. The paper aimed to draw the distinction between these two processes and locate their main characteristics and constituents.
Proteins are the basic components of almost all cell structures. The variety of chemical reactions inside the cells is determined by enzymes, and each type of enzyme leads to one or several separate reactions. The structure of a particular protein is strictly determined, and it can be observed in the specificity of its initial structure – in the sequence of amino acids along the polypeptide, protein chain (Morange, 2009). The specificity of any amino acid sequence is always accurately repeated in all molecules of a given cellular protein.
The Central Dogma was first formulated by Francis Crick in 1958 and was aligned with the accumulated data by 1970 (Morange, 2009). The Central Dogma describes the unified rule of genetic information realization that can be observed in nature; it states that the information can be transmitted from nucleic acid to protein, but never contrariwise. The transfer of genetic information from DNA to RNA and from RNA to protein is universal for all cellular organisms, and it is laid in the foundation of the macromolecule biosynthesis. The genome replication corresponds with the transfer of information from DNA to DNA. It is also possible to observe the informational transfers from RNA to RNA or RNA to DNA (i.e. in some viruses), as well as the transformation of proteins conformation transmitted from one molecule to another.
Transcription and Translation
Transcription is the process of regeneration of the information kept as a single-stranded molecule in DNA and RNA (informational RNA that transfers information about the protein structure from the cell core to the cytoplasm, and the ribosomes). This process is reflected in the molecular and RNA synthesis on a DNA matrix. Molecule and RNA consist of nucleotides that include phosphoric acid residue, sugar, ribose, and one of four nucleobases (A, G, C, and U).
RNA synthesis is based on the principle of complementarity. It means that if one chain of the DNA molecule contains the sequence of four kinds of nucleotides, the second chain of nucleotide sequence will be unambiguously determined so that each A of the first DNA chain will correspond with T in the second, G in the first DNA chain with C in the second, and vice versa.
While the molecules are recognized according to the complementarity principle in the transcription processes, in translation, the molecular recognition is manifested in the process of enzymatic assembly. Transfer RNA molecules consist of a head comprised of an anticodon triplet sequence, and a tail of a particular shape (Blanchard, Kim, Gonzalez, Puglisi, & Chu, 2004). Each shape of the tRNA tail is conformed to a type of codon enzyme that assembles amino acids with tRNA tails. One form of codon corresponds with only one form of particular amino acid. RNA thus carries information not merely in the anticodon nucleotide sequence but also in the form of molecular tail, and the basic information transfer, in this case, happens by reproducing amino acid sequence in protein through enzyme encoding.
References
Blanchard, S. C., Kim, H. D., Gonzalez, R. L., Puglisi, J. D., & Chu, S. (2004). tRNA dynamics on the ribosome during translation. Proceedings of the National Academy of Sciences of the United States of America, 101(35), 12893–12898. Web.
Morange, M. (2009). The Central Dogma of molecular biology. Resonance: Journal of Science Education, 14(3), 236-247.