Courtesy : Bachelor of Science Microbiology (CBM) – Chemistry, Botany, Microbiology
Molecular biology /məˈlɛkjʊlər/ is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physical structure of biological macromolecules is known as molecular biology.# ISO certification in India
Molecular biology was first described as an approach focused on the underpinnings of biological phenomena – uncovering the structures of biological molecules as well as their interactions, and how these interactions explain observations of classical biology.# ISO certification in India
In 1945 the term molecular biology was used by physicist William Astbury. In 1953 Francis Crick, James Watson, Rosalind Franklin, and colleagues, working at Medical Research Council unit, Cavendish laboratory, Cambridge (now the MRC Laboratory of Molecular Biology), made a double helix model of DNA which changed the entire research scenario. They proposed the DNA structure based on previous research done by Rosalind Franklin and Maurice Wilkins. This research then lead to finding DNA material in other microorganisms, plants and animals.# ISO certification in India
Molecular biology is not simply the study of biological molecules and their interactions; rather, it is also a collection of techniques developed since the field’s genesis which have enabled scientists to learn about molecular processes. In this way it has both complemented and improved biochemistry and genetics as methods (of understanding nature) that began before its advent. One notable technique which has revolutionized the field is the polymerase chain reaction (PCR), which was developed in 1983. PCR is a reaction which amplifies small quantities of DNA, and it is used in many applications across scientific disciplines.# ISO certification in India
The central dogma of molecular biology describes the process in which DNA is transcribed into RNA, which is then translated into protein.
Molecular biology also plays a critical role in the understanding of structures, functions, and internal controls within individual cells, all of which can be used to efficiently target new drugs, diagnose disease, and better understand cell physiology. Some clinical research and medical therapies arising from molecular biology are covered under gene therapy whereas the use of molecular biology or molecular cell biology in medicine is now referred to as molecular medicine.# ISO certification in India
History of molecular biology
Main article: History of molecular biology
Molecular biology sits at the intersection of biochemistry and genetics; as these scientific disciplines emerged and evolved in the 20th century, it became clear that they both sought to determine the molecular mechanisms which underlie vital cellular functions Advances in molecular biology have been closely related to the development of new technologies and their optimization. Molecular biology has been elucidated by the work of many scientists, and thus the history of the field depends on an understanding of these scientists and their experiments. # ISO certification in India
The field of genetics arose as an attempt to understand the molecular mechanisms of genetic inheritance and the structure of a gene. Gregor Mendel pioneered this work in 1866, when he first wrote the laws of genetic inheritance based on his studies of mating crosses in pea plants. One such law of genetic inheritance is the law of segregation, which states that diploid individuals with two alleles for a particular gene will pass one of these alleles to their offspring. Because of his critical work, the study of genetic inheritance is commonly referred to as Mendelian genetics.# ISO certification in India
A major milestone in molecular biology was the discovery of the structure of DNA. This work began in 1869 by Friedrich Miescher, a Swiss biochemist who first proposed a structure called nuclein, which we now know to be (deoxyribonucleic acid), or DNA. He discovered this unique substance by studying the components of pus-filled bandages, and noting the unique properties of the “phosphorus-containing substances”. Another notable contributor to the DNA model was Phoebus Levene, who proposed the “polynucleotide model” of DNA in 1919 as a result of his biochemical experiments on yeast. In 1950, Erwin Chargaff expanded on the work of Levene and elucidated a few critical properties of nucleic acids: first, the sequence of nucleic acids varies across species. Second, the total concentration of purines (adenine and guanine) is always equal to the total concentration of pyrimidines (cysteine and thymine).This is now known as Chargaff’s rule. In 1953, James Watson and Francis Crick published the double helical structure of DNA, using the X-ray crystallography work done by Rosalind Franklin and Maurice Wilkins. Watson and Crick described the structure of DNA and conjectured about the implications of this unique structure for possible mechanisms of DNA replication.# ISO certification in India
J. D. Watson and F. H. C. Crick were awarded Nobel prize in 1962, along with Maurice Wilkens, for proposing a model of the structure of DNA.
In 1961, it was demonstrated that when a gene encodes a protein, three sequential bases of a gene’s DNA specify each successive amino acid of the protein. Thus the genetic code is a triplet code, where each triplet (called a codon) specifies a particular amino acid. Furthermore, it was shown that the codons do not overlap with each other in the DNA sequence encoding a protein, and that each sequence is read from a fixed starting point.# ISO certification in India
During 1962–1964, through the use of conditional lethal mutants of a bacterial virus, fundamental advances were made in our understanding of the functions and interactions of the proteins employed in the machinery of DNA replication, DNA repair, DNA recombination, and in the assembly of molecular structures. # ISO certification in India
