What is Molecular Biology?
Molecular Biology studies the molecular basis of the vital activity of organisms. Ch. areas of research are related to the study of the mechanisms of storage, reproduction, and transmission of genetics. Information. Based on this, M.’s object of research. are nucleic acids – deoxyribonucleic (DNA) and ribonucleic (RNA) – and proteins, as well as their macromolecular complexes – chromosomes, ribosomes, and multienzyme systems that provide biosynthesis of nucleic acids and proteins.
- b. borders, and in terms of objects and methods of research partially coincides with molecular genetics, virology, the taxonomy of organisms, biochemistry, cell biology, biophysics, and bioorganic. chemistry, crystallography, computer modeling, bioinformatics, etc. M. b. not only depends on the progress of these sciences but also has a significant impact on their development, setting them very non-trivial tasks
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History of Molecular Biology
M.’s date of emergence. 1953 is considered to be when J. Watson and F. Crick correctly interpreted the X-ray data of R. Franklin and M. Wilkins and built a model of the spatial structure of DNA in the form of a double helix. Based on this model, they proposed a simple matrix mechanism for its replication (doubling), based on the principle of complementarity of heterocyclic DNA bases. That. for the first-time funds. biological phenomenon (heredity) was described at the molecular level in simple chemicals. terms.
This discovery, one of the largest in the history of natural science, was preceded by a long period of research in the field of biochemistry, cytology, genetics, and chemistry of nucleic acids, which led to the establishment of genetics. the role of DNA. K ser. 1930s discovery by the founder of M. b. in Russia, A. N. Belozersky DNA in plants (previously it was believed that DNA is present only in the nuclei of animal cells) led to the assertion of that fundam. that DNA is found in every living cell. At the beginning the 1940s the universality of distribution in wildlife and RNA was also proved.
In 1944 Amer. microbiologist O. T. Avery and his staff carried out genetic. transformation of bacteria using pure DNA, thereby demonstrating that it is the carrier of heredity.
By the beginning of the work of Watson and Crick in the laboratory of E. Chargaff, the nucleotide composition of DNA from many organisms was studied and it was proved that in any DNA the molar fractions of purine and pyrimidine bases – adenine and thymine, guanine and cytosine, are equal to each other (A \u003d T, G =C; the so-called Chargaff rule). Watson and Crick showed that it is these bases, being located opposite each other in different chains of the DNA molecule, that are complementary. By 1953, A. Todd and his school established the principles of chemistry. structures of nucleic acids, also used in the construction of the DNA double helix model.
About Molecular Biology
Research in this area covers a wide variety of topics where molecular methods are used, including genetics of formation, adaptation, evolutionary and developmental biology, microbiology, biodiversity monitoring, and ecology.
We use a wide variety of cutting-edge techniques such as eDNA, prokaryotic and eukaryotic genome sequencing and assembly (using long and short methods), and genetic manipulation of plant and animal models.
Researchers have access to recently renovated laboratories and research rooms, including eDNA cleanrooms; confocal microscopy rooms; temperature-controlled rooms; greenhouses; marine and freshwater aquariums; houses of small mammals; and venomous and non-venomous reptile rooms.
The Formation of Molecular Biology as a Science
An important step in the development of M.’s bases. F. Crick (1955) postulated the way of transmission of genetics. information from DNA to proteins through RNA synthesized on DNA using the matrix mechanism (the so-called central dogma of M. b.: DNA → RNA → protein).
The work of J. Watson and F. Crick gave rise to a wave of experiments, unprecedented in scale and productivity. works (comparable only to the situation in atomic physics in the 1930s–40s). Already to the horse. The 1950s it was proved that DNA replication proceeds with the unwinding of the double helix and the synthesis of two daughter DNA molecules on each of the strands according to the matrix principle (thus, N. K. Koltsov’s hypothesis of the matrix mechanism of chromosome replication, put forward in 1927, was experimentally substantiated); a DNA polymerase enzyme capable of carrying out this process has been described;
Proposed a method of molecular DNA–DNA and DNA–RNA hybridization based on the ability of complementary polynucleotides to specifically bind to each other; were found in matrix (information) RNA (mRNA), in which the information encoded in DNA about the structure of proteins is rewritten, and the enzyme RNA polymerase, which catalyzes the synthesis of RNA on DNA (transcription); it was proved that protein synthesis (translation) occurs on ribosomes (complexes of non-coding proteins of ribosomal RNA with special ribosomal proteins) also according to the template mechanism, transfer RNAs (tRNAs) were discovered that specifically accept amino acids, with the help of which this mechanism is implemented.
In the beginning. 1960s Amer. scientists P. Doty and J. Fresco, A. S. Spirin, and others established the principles of organization of the macromolecular structure of RNA. In 1961, F. Jacob and J. Monod published a scheme for the regulation of protein synthesis at the level of transcription, which, after several. years has been experimentally proven, thanks to the discovery of repressor proteins and transcription activator proteins; it was shown that RNA polymerase itself is a regulator of gene activity (R. B. Khesin-Lurie, 1961). Based on these works, the specific problem was formulated. Nucleic-protein recognition – physical. phenomena through which many are realized. stages of genetic transmission. information in the cell. In the 1st floor.
In the 1960s the decoding of the amino acid genetic code was completed (M. U. Nirenberg, S. Ochoa, H. G. Koran), one of the main. the laws of living nature that govern the translation of the nucleotide “language” of nucleic acids into the amino acid “language” of proteins, and to con. In the 1960s all stages of translation are described in detail; the reconstruction of ribosomes from RNA and proteins outside the cell was carried out; disclosed the fundamental points of such processes of transformation of DNA as the repair of damage in its molecules, the mechanisms of restriction-modification, and genetic. recombination; nucleosomes have been described. regulatory structural elements of chromatin. By the same time, effective systems for the cell-free synthesis of nucleic acids and proteins were created, which became an important tool for M.. In 1970, Kh. M. Temin and D. Baltimore discovered RNA-dependent DNA polymerase in oncogenic viruses and thus showed that, in principle, the flow of genetic. Information can also be transferred from RNA to DNA.