Research at the molecular level the structure and function of biological macromolecules, which reveals the essence of the phenomenon of life science. Major study of protein and DNA structure and function, membrane structure and function, and studied at the molecular level the basic characteristics of biosphere.
Translated by Google
Molecular biology (molecular biology)
Research at the molecular level the phenomenon of life science. Through the study of biological macromolecules (nucleic acids, proteins) of the structure, function and biosynthesis of various aspects to clarify the nature of the phenomenon of life. The study includes a variety of life processes. Such as photosynthesis, the molecular mechanisms of development, the mechanism of neural activity, the incidence of cancer, and so on. Molecular biology from the molecular level structure and function of biological macromolecules in order to clarify the nature of the phenomenon of life science. Since the 50's since the 20th century, molecular biology is biology and the growing point of the frontier, the main research areas include protein system, protein - nucleic acid system (center of molecular genetics) and protein - lipid system (ie, biofilm). Biological macromolecules, especially proteins and nucleic acid structure and function of the study is the foundation of molecular biology. Theory of modern chemistry and physics, technology and application of the method to promote the structure and function of biological macromolecules, which appeared in the past 30 years the rapid development of molecular biology. Molecular Biology and Biochemistry and Biophysics, very closely, the main difference between them is: ① biochemistry and biophysics chemistry and physics is the method to study the molecular level, cell level, the overall level or group level of biological problems at different levels. And molecular biology is focused on molecules (including multi-molecular system) level of the universal law of life activities; ② at the molecular level, molecular biology focuses on the macromolecules, mainly proteins, nucleic acids, lipids and some system polysaccharide and its composites. Some small molecules in vivo into the scope of biochemistry is; ③ The main purpose of the study of molecular biology at the molecular level is to clarify the biological characteristics common to have the basic, that is the essence of the phenomenon of life; and research a a particular kind of biological organism or a body organ of a particular physical and chemical phenomena or changes are, however, the scope of biophysics or biochemistry.
Translated by Google
A brief history
Structural analysis and study of genetic material in the development of molecular biology has made important contributions. The central element structural analysis of biological molecules through the clear three-dimensional structure to explain the physiological function of cells. WH 1912, the United Kingdom and WL Bragg Bragg X-ray crystallography established the successful determination of a number of very complex molecules and protein structure. After the students Bragg WT Astbury and JD respectively Bernard and hair, muscle fiber protein and pepsin, tobacco mosaic virus, a preliminary structural analysis. Their work was crystallography of biological macromolecules laid the foundation for the formation and development. 50 years of molecular biology as an independent branch of the era come to the fore and the rapid development. The first is in the protein structure analysis, LC 1951, Pollin and other α-helix structure is proposed to describe the protein molecule of a peptide chain conformation. F. Sanger in 1955, completed the determination of the amino acid sequence of insulin. JC Kendrew and MF Perutz and then X-ray analysis in the application of heavy atom isomorphous replacement and computer technology in 1957 and 1959, respectively, explained whale myoglobin and horse hemoglobin in the three-dimensional structure. Synthesized in 1965, Chinese scientists have biological activity of insulin, first realized the synthetic protein. On the other hand, M. Delbrück group _select_ed from phage 1938 as the object began to explore the mystery of genes. After phage infection of the host to replicate within half an hour to hundreds of offspring of the same phage particle, it is ideal for graduate students self-replicating material objects. 1940 GW Beadle and EL Tatum proposed the "one gene, one enzyme" hypothesis, that gene's function is to determine the enzyme structure, and only one gene determines a structure of the enzyme. But at the time the nature of genes is not clear. 1944 OT Avery and other research into the phenomenon in bacteria, DNA is the genetic material proved. 1953 JD Watson and FHC Crick proposed the double helix structure of DNA, creating a new era of molecular biology. On this basis, the center of the proposed rule, describes the genetic information from genes to protein structure of the flow. The clarification of the genetic code is revealed in vivo genetic information for storage. 1961 F. Jacob and J. Monod operon concept put forward to explain the prokaryotic gene expression. To the mid-20th century, 60, on the DNA self-generated RNA replication and transcription has been basically clear the general nature of the gene also will be starting the mystery solved. Only 30 years or so, molecular biology, the science has gone from a bold hypothesis, after a large number of experiments to study to establish the theoretical foundation of the discipline. Into the 70's, due to breakthroughs in recombinant DNA research, genetic engineering has borne fruit in practical applications, according to the wishes of the modified protein engineering of protein structures has become a reality.
Translated by Google
Elements
Unit of protein structure of proteins is the α-amino acids. A total of 20 kinds of amino acids in common. They can be in a different order of life to provide the astronomical world, a variety of proteins. The organization of the molecular structure of proteins can be divided into four main levels. Primary structure, also known as chemical structure, is the sequence of amino acid molecules. Both linked to the amino acid condensation through the formation of amino and carboxyl chain structure, called peptides. Peptide main chain atoms of the local spatial arrangement of the secondary structure. Secondary structure in the space are coiled and curled for the tertiary structure. Some protein molecules is the same or different subunits assembled into, and the relationship between sub-units called quaternary structure. Proteins and physiological functions of the special nature of the particular structure of its molecules are closely related, which is all kinds of proteins they are able to demonstrate a variety of activities, the molecular basis of life. Of protein structure and function in molecular biology is an important content. With the development of structural analysis technology and now has thousands of chemical structure of proteins and hundreds of three-dimensional protein structure has been elucidated. Since the late 70s, the use of complementary DNA sequence determination of the chemical structure of the protein inverse method, not only improves the efficiency of the analysis, but also some of the amino acid sequence analysis of the conditions are met is not easy analysis of the chemical structure of the protein can be achieved. Discovery and identification of proteins with new features, is still the study of protein content. For example, with gene regulation and higher nervous activity of the protein is highly regarded. Protein - nucleic acid system, the genetic characteristics of organisms determined mainly by the nucleic acid. The vast majority of genes by DNA biological composition. Simple virus, such as the λ phage genome is 46000 nucleotides composed of a certain order one double-stranded DNA (as is the double-stranded DNA, usually to base the calculation of its length.) Bacteria such as E. coli genome, containing 4 × 106 base pairs. DNA contained in chromosomes of human cells for the 3 × 109 base pairs. Genetic information to offspring life activities in and out, need replication, transcription and translation. DNA replication is the parent molecule as the template synthesis of progeny DNA. Transcription is the DNA nucleotide sequence of decisions based on a class of RNA molecules in the nucleotide sequence; the latter was further decided that the sequence of amino acids protein that is translated. Because this type of RNA plays a role in information transmission, it is called messenger RNA (mRNA). Since the nucleotide composition of 4 RNA species, and there are 20 amino acids in proteins, and their correspondence is a certain mRNA molecules in the nucleotide sequence of the 3 connected to determine an amino acid, which is triplet genetic code. Protein - lipid system prevailing in vivo membrane structure, referred to as biofilm. It includes the cell membrane and cell periphery with a variety of specific functions within the organelle membrane. View from the chemical composition, lipids and membrane proteins by non-covalent bond through a system composed of. Many film also contains a small amount of carbohydrates to form glycoproteins or glycolipids. 1972 fluid mosaic model proposed outlines the basic features of the biofilm: The basic skeleton is the lipid bilayer structure. Membrane proteins embedded into the table in the protein and protein. Membrane lipids and membrane proteins are in a constant state of motion. Biofilm structure and function has both sides of the asymmetry. Send in material, for example, some substances can pass through the membrane at high speed, while others can not. Like kelp from the iodine concentration in seawater 3 times. _Select_ive membrane permeability to intracellular pH and ion composition is relatively stable, maintaining the nerve, muscle excited ionic gradients necessary to ensure that the cell concentration of nutrients and eliminate waste functions. Another important function of biofilm cells or between the transmission of information within and outside the cell membrane. On the cell surface, there is a wide class of proteins known as receptors. The role of hormones and drugs had to go through specific binding with the receptor molecule achieved. Cancer cell surface receptor significant changes in the distribution of material. Membrane surface properties on cell division is also an important regulatory role in reproduction. On the cell surface properties of sugar led. Glycoproteins, proteoglycans and glycolipids and other biological macromolecular structure and function of more and more attention. From the development trend, the formation of oligosaccharides with proteins or lipids in the system will become a new molecular biology of important areas.
Translated by Google
Theory and application to
Molecular Biology of the accomplishments: the fundamental laws of life activities in various organisms are unified. For example, whatever the organism, by the same amino acid and nucleotide composition of the protein and nucleic acids, respectively. Genetic material, except for some viruses, but are DNA, and in all the cells in the same biochemical mechanism of replication. Central dogma of molecular genetics and genetic codes, except for a few exceptions, in most cases are also common. The achievements of physics prove that atoms of all substances by the small number of elementary particles formed under the same law, the material shows a high degree of consensus on the structure of the world, revealing the nature of the material world, which led to the development of the physics . Molecular biology at the molecular level will reveal the basic structure of life and the world the fundamental laws of life activities highly consistent, revealing the essence of the phenomenon of life. And past studies of elementary particles, like driving the development of physics, molecular biology concepts and ideas that have already infiltrated into the basic and applied areas of each branch of biology, led to the development of the biology, so that to a new level. In the application, the principle of energy conversion to clarify the biofilm, will help solve global energy problems. Understand the principles of the catalytic activity can be more targeted to the artificial simulation of the chemical industry on the design of new catalysts are widely used and thus to bring about a revolution in the chemical industry. Molecular biology in bio-engineering technology also played a huge role, recombinant DNA technology in 1973 successfully for the development of genetic engineering has paved the road. 80 years, genetic engineering techniques have been adopted, some of the higher animal genes into single-cell organisms, with the fermentation production of interferon, a variety of peptide hormones and vaccines. For the further development of genetic engineering oriented cultivation of animals, plants and microorganisms seed and effective control and treatment of some human genetic diseases to provide a fundamental solution. From the perspective of gene regulation cell cancer has also been made considerable progress. Human molecular biology will ultimately make an important contribution to the conquest of cancer.
Translated by Google
Application of Molecular Biology
1, the paternity testing In recent years, the progress of human genome research advances, and constantly improve the technology of molecular biology, genomic research to various disciplines with the continuous infiltration of the progress of these subjects reached an unprecedented height. In forensic science, STR loci and single nucleotide (SNP) locus are the second and third-generation DNA analysis of the core, is the second RFLPs (restriction fragment length polymorphism) VNTRs (variable number of tandem repeat polymorphism) of the developed detection technology. Zuowei the forefront of the criminal biotechnology, DNA analysis of forensic material evidence examination provides a scientific, reliable and efficient means by which evidence identification from the individual excluded from the transition to a can for the same certified level, DNA testing can be directly identified crime as murder, rape, murder, chopping the case, rape, pregnancy and other major cases detected in difficult cases to provide accurate and reliable basis. With the development and application of DNA technology, DNA testing will be marking systems important means and ways of detecting them. This method as a paternity test is already very mature, and it is the best internationally recognized methods.
Translated by Google
Medical Dictionary
Molecular biology research in all areas of biology have a profound impact. Such as different types of bio-genetic relationship between the past, based mainly in the form of different types of biological structures to determine the similarities and differences. This morphological structure is relatively simple organisms such as bacteria have difficulties. Through the different types of protein or nucleic acid molecules of biological determination can overcome these difficulties, and can more objectively reflect the biological inter-related. Molecular biology and medicine, agriculture and biological engineering very closely.
Translated by Google
Encyclopedia
fenzi shengwuxue Molecular Biology molecular biology Life activities from the molecular level and the rules and disciplines. The main structure of biological macromolecules, function and organization and interaction with each other; the molecular basis of heredity; biofilm structure and function of other issues. Core is through the proteins, enzymes, nucleic acid structure and function of biological macromolecules research to explore the nature of the phenomenon of life.
germ