Apr 08, 2019 dna or deoxyribonucleic acid is the basic hereditary material present in all the cells of an organism and basically provides a blue print for the cells functions, growth, reproduction and death. This is critical when cells divide because each new cell needs to have an exact copy of the dna present in the old cell. Dna and rna can be represented as simple strings of letters, where each letter corresponds to a particular nucleotide, the monomeric component of the nucleic acid polymers. Yakubovskaya2 1lomonosov moscow state university, department of chemistry, 119991 moscow, russia. The helical structure of dna is variable and depends on the sequence as well as the environment. Ghada abou elella lecturer of biochemistrylecturer of biochemistry faculty of vet. Dna structure, functions and properties slideshare.
This structure is known as bdna, and represents an average conformation of dna, based on. Dna is a completely informational molecule, in that it. Adenine is always opposite thymine, and cytosine is always oppostie guanine. Nucleic acids were first isolated by friedrich miescher 1869 from pus cells. The structure and function of dna molecular biology of the. Some aspects of physicochemical properties of dna and rna. Dna can deviate from the ideal watsoncrick structure. Note the difference in groove width and the relative displacements of the base pairs from the central axis. The latter determines the sequencedependent physicochemical properties of dna, for example its stiffness and susceptibility to strand separation. Im going to give you the structure of that first, because you will need it later anyway. Early evidence suggesting an rna intermediate between dna and proteins 1. Structure, properties, and biological relevance of the dna and rna gquadruplexes. If youre seeing this message, it means were having trouble loading external resources on our website.
Dna assembly of nanoparticles is a powerful approach to control their properties and prototype new materials. From 1940 to 1953, many scientists were interested in unraveling the structure of dna molecule. If you continue browsing the site, you agree to the use of cookies on this website. Dna and rna are both nucleic acids, which are the polymeric acids isolated from the nucleus of cells. Deoxyribonucleic acid dna is best known for its central role in the encoding, storage, replication, and propagation of genetic information within all known, independently living organisms. Dna packaging enables dna to act as an energy store to facilitate the. All of these features were described by watson and crick. Watson and crick proposed that dna is made up of two strands that are twisted around each other to form a righthanded helix. The structure of dna was described in 1953, leading to further understanding of dna replication and hereditary control of cellular activities.
Crucially, both the coding of proteins and rna molecules and also the physicochemical properties of the polymer are specified by the base sequence. Structure, function, packaging and properties with diagram. Read this article to learn about the history, types, structure, silent features and functions of dna. Jul 02, 2012 a second information level is present in the different properties of the intrinsic dna structure, where the dna sequence itself only plays a supporting role. Pictures of the double helix of deoxyribonucleic acid dna havebecomesocommonthateveryoneisfamiliar with its overall shape and structure figure 1a. The dna structure was determined by watson and crick in. Hertwig 1884 proposed nuclein to be the carrier of hereditary traits. Medicine south valley universitysouth valley university 2. The most important feature of dna is that it is usually composed of two polynucleotide chainstwisted around each other in the form of a double helix figure 61. However, dna is also a chemical material that can be produced in industrial quantities by welldeveloped. The structure of rna rna, like dna, is a polymer consisting of nucleotides joined together by phosphodiester bonds. Dna, organic chemical of complex molecular structure found in all prokaryotic and eukaryotic cells.
Structure and replication dna was known to be a chemical in cells by the end of the nineteenth century, has the capacity to store genetic information, and can be copied and passed from generation to generation. Most importantly dna chirality enables the formation of supercoiling under torsional stress. Introduction to dna structure duke computer science. Pdf the proposal of a doublehelical structure for dna over 60. An important property of dna is that it can replicate, or make copies of itself. Some aspects of physicochemical properties of dna and rna sandipta acharya. Structure, properties, and biological relevance of the dna. The discovery of dna structure 55 years ago marked the beginning of a process that has transformed the foundations of biology and medicine, and accelerated the development of new. Dna structure and function, a timely and comprehensive resource, is intended for any student or scientist interested in dna structure and its biological implications. Dna was known to be a long polymer composed of only four types of subunits, which resemble one another chemically. Their main function is to maintain and transmit the genetic code. Institute for research in biomedicine irb barcelona, 08028 barcelona, spain bsccrgirb joint program in computational biology, institute for research in biomedicine, 08028 barcelona. Dna controls cellular activities, including reproduction. Dna structure and replication pbworks pages 1 5 text.
Left, a twodimensional representation of the two complementary strands of dna, showing the at and gc base pairs. Read and learn for free about the following article. A second information level is present in the different properties of the intrinsic dna structure, where the dna sequence itself only plays a supporting role. Whereas dna nucleotides contain deoxyribose sugars, rna nucleotides have ribose sugars. It is these properties that play a major role in the biological function of dna.
Dna bases pair up with each other, a with t and c with g, to form units called base pairs. The clues in franklins xray pattern enabled watson and crick to build a model that explained the specific structure and properties of dna. Dna or deoxyribonucleic acid is the basic hereditary material present in all the cells of an organism and basically provides a blue print for the cells functions, growth, reproduction and death. A, b and zdna helix families david w ussery,danish technical university, lyngby, denmark there are three major families of dna helices. Each base is also attached to a sugar molecule and a phosphate molecule.
An embryo uses dna and rna similar structure as dna with a small difference instructions to make proteins transform into an organism. This page, looking at the structure of dna, is the first in a sequence of pages leading on to how dna replicates makes copies of itself, and then to how information stored in dna is used to make protein molecules. Dna structure, properties, types and functions dna stands for deoxyribonucleic acid which is a molecule that contains the instructions an organism needs to develop, live and reproduce. Deoxyribose is a modified form of another sugar called ribose. With the 50th aniversary of the discovery of the dna structure by james. Today, we know much about dna, its properties, and function. Dna was in the nucleus but proteins were made in the cytoplasm 2. This information is stored in the form of long polymer chains. However, the structure and properties of dna assembled nanoparticles are labile and sensitive to interactions with counterions, which vary with processing and application environment. The full name of dna, deoxyribonucleic acid, gives you the name of the sugar present deoxyribose. The two dna strands are antiparallel, such that the 3.
Maurice wilkins and rosalind franklin by xray diffraction method gave the double helical nature of the dna. Dna stands for deoxyribonucleic acid, while rna is ribonucleic acid. Importance of dna rna 3d structure nucleic acids are essential materials found in all living organisms. This is a comparison of the differences between dna versus rna, including a quick summary and a detailed table of the differences. Dna structural properties in the classification of genomic. The double helix structure of a dna molecule was later discovered through the experimental data by james watson and francis crick. The structure of the dna called the doublestranded helical structure was first described by watson and crick in 1953. Dna structure, functions and properties by professordr. Dec 08, 2017 dna bases pair up with each other, a with t and c with g, to form units called base pairs.
The discovery of dna as the hereditary material ushered in the new field of molecular biology, the. The dna structure at left schematic shown will selfassemble into the structure visualized by atomic force microscopy at right. This material is aimed at 16 18 year old chemistry students. Jan, 2020 dna structure, properties, types and functions.
Each strand of dna in the double helix can serve as a pattern for duplicating the sequence of bases. Early in the 1950s, dna was first examined by xray diffraction analysis, a technique for determining the threedimensional atomic structure of a molecule discussed in chapter 8. Dna structure and function if youre seeing this message, it means were having trouble loading external resources on our website. As we shall see in this chapter, there are in fact variations on common themes of structure that arise from the unique physical, chemical, and topological properties of the polynucleotide chain. Transcription is the synthesis of rna using dna as a template. These instructions are found inside every cell, and are passed down from parents to their children. Structure, function, packaging and properties with. Its orientation, width, width between nucleotides, length and number of nucleotides per helical turn is constant.
Dna structure and function of deoxyribonucleic acid dna. Engineering the structure and properties of dnananoparticle. The latter determines the sequencedependent physicochemical properties of dna, for example, its stiffness and susceptibility to strand separation. Dna structure, properties, types and functions molecular. The book provides a simple yet comprehensive introduction to nearly all aspects of dna structure. They were erwin chargaff, maurice wilkins, rosalind franklin, linus pauling, francis crick and james watson. Model 1 the structure of dna ladder model of dna helix model of dna nucleotide phosphatedeoxyribose nitrogensugar containing basenitrogen bases adenine thymine guanine cytosine 1.
Introduction pictures of the double helix of deoxyribonucleic acid. Both have sets of nucleotides that contain genetic information. Dna stands for deoxyribonucleic acid which is a molecule that contains the instructions an organism needs to develop, live and reproduce. In 1953, two of them james watson and francis crick, proposed that the. This topic explains the structure of dna and its properties. Structure and function of genes and chromosomes 19 a hydrogen bonds c c t c 5 5 3 3 3. Medical college, university of mauritius, mauritius biochemistry for medics. Structure of dna, functions and properties slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. If youre behind a web filter, please make sure that the domains.
Structure and function ofstructure and function of dnadna dr. This new organism has all the characteristics of its parents, for this reason, a human has a human baby and a plant produces seeds. Although dna and rna both carry genetic information, there are quite a few differences between them. Dna was first recognized and identified by the swiss biologist, johannes friedrich miescher in 1869 during his research on white blood cells. The backbone of dna is based on a repeated pattern of a sugar group and a phosphate group. Organisation of dna in microbial genomes and genetic transfer 5. Dna duplex does not lose its structure completely, and the two strands remain bound when dna is transferred from aqueous solution to the gas phase. Nucleic acid, naturally occurring chemical compound that is capable of being broken down to yield phosphoric acid, sugars, and a mixture of organic bases purines and pyrimidines. Most people are familiar with the doublehelical model of a doublestranded dna. The structure of dna was given by james watson and francis crick in 1953, for which he received the nobel prize, basing on the discoveries of. Note that the orientation of the two strands is antiparallel. Dna structure and properties basic predicting melting. Dna structure and function leads the reader from the early models of the double helix, through curvature, supercoiling, cruciforms, z dna and triplex dna to the more esoteric alternative conformations of 1995. Structure and properties of dna and genes slide 2 dna is the fundamental genetic material of all types of life.
Dna is a double helix, while rna is a single helix. Mar 02, 2012 dna structure, functions and properties 1. With a free hydroxyl group on the 2carbon atom of the ribose sugar, rna is degraded rapidly under alkaline. Nucleic acids are the main informationcarrying molecules of the cell, and, by directing the process of protein synthesis, they determine the inherited characteristics of every living thing. Dna structure is as varied as protein structure, and nucleic acids can catalyze chemical reactions ribozymes bacterial and animal cells store and process dna slightly differently, although both use similar ribosomes and the same genetic code modern molecular biology allows us to express. Chapter 2 structures of nucleic acids nucleic acids. Indeed, there is no one generic structure for dna and rna. It codes genetic information for the transmission of inherited traits.
Rna synthesis in the nucleus was exported to the cytoplasm. It also explains current ideas on the biological significance of classic and alternative dna conformations. Rna properties, structure, types and functions rna or ribonucleic acid is a polymer of nucleotides which is made up of a ribose sugar, a phosphate, and bases. Deoxyribonucleic acid, also abbreviated as dna, is the principal informational macromolecule of the cell, which stores, translates and transfers the genetic information. Dna and protein synthesis life is a three letter word. Two pyrimidines thymie and cytosine and two purines adenine and guanine. Dna structure and function travers 2015 the febs journal. When dna is subjected to extremes of ph or temperatures above 80 to 90 degree centigrade, it gets denatured and the double helical structure is unfolded due to disruption of hydrogen bonds between the bases and the hydrophobic interactions of the bases. Although the information they carry is onedimensional, it is essential to understand the 3d structure of nucleic. Dna structure and properties basic predicting melting temperature. These dna structural properties are various characteristics of the molecular structure that can be assigned a numeric value based on theoretical simulations or experimental measurements. It is quite a journey, and richard sinden is an informed and entertaining guide. Dna nanotechnology is the field that seeks to design nanoscale structures using the molecular recognition properties of dna molecules. So howdoes the structure of dna allow it to copy itself so accurately.