Chemical structure of dna and rna pdf

The subtle structural difference between the sugars gives dna added stability, making dna more. From 1940 to 1953, many scientists were interested in unraveling the structure of dna molecule. Dna stands for deoxyribonucleic acid, while rna is ribonucleic acid. The nucleotides are linked in a directional manner via phosphodiester bonds between their sugars.

Muskhelishvili in both the bacterial nucleoid and the eukaryotic nucleus, dna is usually packaged as a negative super. As we shall see in this chapter, there are in fact vari ations on common themes of structure that arise from the unique physi cal, chemical. As shown in the animation, dna is a polymer of units called nucleotides, which contain deoxyribose sugars and nitrogenous bases. The fourth base in rna, however, is not thymine but instead the pyrimidinederived base, uracil u. Jan 18, 2018 indeed, the authors of the new study suggest that the noncanonical nucleosides could have played a crucial role in the phase of chemical evolution that preceded the emergence of the rna world, a. Rna properties, structure, types and functions molecular. Importance of dna rna 3d structure nucleic acids are essential materials found in all living organisms. Rna on its own can act as a catalyst for certain chemical reactions. The structure of dna is dynamic along its length, being capable of coiling into tight loops and other shapes. Systematic chemical studies indicate that the capability of watsoncrick basepairing is widespread among potentially natural nucleic acid alternatives taken from rna s close structural neighborhood. The ribose sugar of rna is a cyclical structure consisting of five carbons and one oxygen. Oh group attached to the second carbon group in the ribose sugar molecule makes rna prone to hydrolysis. All of these features were described by watson and crick. Chemical etiology of nucleic acid structure science.

Name the three types of rna and identify the role of each in. Jul 06, 2018, what is dna structure and function bio in hindi duration. Although the information they carry is onedimensional, it is essential to understand the 3d structure of nucleic. A ribonucleotide in the rna chain contains ribose the pentose sugar, one of the four nitrogenous bases a, u, g, and c, and a phosphate group.

The chemical evolution of dna and rna on early earth. The chemical structure of rna is very similar to that of dna, but differs in three primary ways. In rna, the pentose is ribose, whereas in dna it is 2deoxyribose. Functions of dna and summary of structure dna consists of four basesa, g, c, and tthat are held in linear array by phosphodiester bonds through the 3 and 5 positions of adjacent deoxyribose moieties. Both are composed of unbranched chains of units called nucleotides, each of which contains. If you stretch out all the strands of dna in your body and link them together, it would stretch to 110 billion miles. The 2oh group of rna facilitates chemical cleavage in aqueous naoh by forming a cyclic phosphate ester. Adenine is always opposite thymine, and cytosine is always oppostie guanine. Although dna and rna both carry genetic information, there are quite a few differences between them. Besides its chemical composition, rna has important similarities and di. Indeed, there is no one generic structure for dna and rna.

They determine that dna is a double helix structure the two dna strands 5,6 are spirally attached to each other and on the base of the nucleotide hydrogen bond is the bond which holds the structure of the. 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. Their creation is a continuous process, and a single protein chain can have 1015 amino acids added to it per second via the process outline above. Unlike doublestranded dna, rna is a singlestranded molecule in many of its biological roles and consists of much shorter chains of nucleotides. Relationship with base composition and structure elena a. Dna is a long polymer made from repeating units called nucleotides, each of which is usually symbolized by a single letter. In all species it is composed of two helical chains, bound to each other by hydrogen bonds. Rna, complex compound of high molecular weight that functions in cellular protein synthesis and replaces dna as a carrier of genetic codes in some viruses. The question of how many strands and how they went together was answered by the xray crystallographic work of rosalind franklin at kings college in. A comparison of rna and such alternatives with regard to chemical properties that are fundamental to the biological function of rna provides chemical facts that may contain clues to rna s origin. The structure of dna is a double strand helix whereas rna is a single strand molecule. Cells access the information stored in dna by creating rna to direct the synthesis of proteins through the process of translation. Read this article to learn about composition and structure of the nucleic acids. This is a comparison of the differences between dna versus rna, including a quick summary and a detailed table of the differences.

This animation explores the chemical components and bonds of the nucleotides that make up dna. These focus on using controlled pore glass and microarrays on glass. Some aspects of physicochemical properties of dna and rna diva. The horizontal line indicates the carbon chain of sugar with base attached to c 1. Both have sets of nucleotides that contain genetic information. Rna consists of ribose nucleotides and the nitrogenous bases adenine, guanine, cytosine, and uracil. Structure of dna and rna nucleic acids basic structure of nucleotides dna and rna are polynucleotides complementary base.

The structure and function of nucleic acids biochemical society. Its orientation, width, width between nucleotides, length and number of nucleotides per helical turn is constant. Nucleic acids have a primary, secondary, and tertiary structure analogous to the classification of protein structure. Dna or rna structure is often represented in a shorthand form. The structure of dna 14 was first discovered by james watson and francis crick in 1953. Indeed, the authors of the new study suggest that the noncanonical nucleosides could have played a crucial role in the phase of chemical evolution that preceded the emergence of. Rna or ribonucleic acid is a polymer of nucleotides which is made up of a ribose sugar, a phosphate, and bases such as adenine, guanine, cytosine, and uracil. Rna has a simpler structure and is needed in order for dna to function. Dna genetic information in genes rna copies of genes proteins functional molecules dna structure one monomer unit deoxyribonucleic acid composed of a base, a sugar deoxyribose, and a phosphate. Three types of chemicals make up the building blocks for nucleic acids. Base pairing might occur between bases along the single strand giving rise to various three dimensional folds. Dna and rna are both nucleic acids, which are the polymeric acids isolated from. Learn about the structure, types, and functions of rna. Quizlet flashcards, activities and games help you improve your grades.

First, like dna, rna has four and only four nucleotides. These nucleic acids are formed by the combination of nitrogenous bases, sugar molecules and the phosphate groups that are linked by different bonds in a series of sequences. Their main function is to maintain and transmit the genetic code. Systematic chemical studies indicate that the capability of watsoncrick basepairing is widespread among potentially natural nucleic acid alternatives taken from rnas close structural neighborhood. Unlike dna, rna exists as a single stranded molecule. Describe the primary structure of dna and rna and secondary and tertiary structure of dna. A chromosome, for example, is a single, long dna molecule, which would be several centimetres in length when unravelled. Chapter 2 structures of nucleic acids nucleic acids. Besides its chemical composition, rna has important similarities and differences with dna. There is some evidence dna may have occurred first, but most scientists believe rna evolved before dna. Mar 24, 2015 their creation is a continuous process, and a single protein chain can have 1015 amino acids added to it per second via the process outline above. Presumably some of these differences are due to enzyme specificities.

Main helical structures of dna and rna are described. Describe the chemical structure of polynucleotides dna and rna and identify the phosphodiester bonding patterns within polynucleotides. Impact of mutations on translation into amino acids. Intro to gene expression central dogma the genetic code. The sequence of bases in the nucleic acid chain gives the primary structure of dna or rna. Rna sometimes forms a secondary double helix structure, but only intermittently. Nucleic acids are the main informationcarrying molecules of the cell and play a central role in determining the inherited characteristics of every living thing. Relative thermodynamic stability of dna, rna, and dna. Paper iii showed that the chemical characters of internucleotidic phosphate are nonyidentical in rna compared to that of dna. It has a distinctive structure and, unlike dna, there are variations and various types of rna structures. Nucleotides can posess 1, 2 or 3 phosphate groups, e. Rna molecule is not the information carrier excepting in few viruses.

As the purpose of this post was primarily to examine the chemical structure of dna, the discussion of replication and protein synthesis has been kept brief and relatively simplistic. Dna is a double helix, while rna is a single helix. Dna is called hereditary material because dna is much more stable then rna. Interference rna irna interferes with the dna message 4. With the discovery of the molecular structure of the dna. Let us take a look at the fascinating nucleic acid structure. This information is transmitted by transcription from dna to rna. Structure of rna the structure of rna nucleotides is very similar to that of dna nucleotides dna and rna play very different roles from one another in modern cells. A comparison of rna and such alternatives with regard to chemical properties that are fundamental to the biological function of rna provides chemical facts that may contain clues to rnas. Intra molecular hydrogen bond interactions are formed between bases of the same single. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Also, rna is found in prokaryotes, which are believed to precede eukaryotes.

They were erwin chargaff, maurice wilkins, rosalind franklin, linus pauling, francis crick and. Rna is typically single stranded and is made of ribonucleotides that are linked by phosphodiester bonds. Deoxyribose sugar 15,16 absence of the oxygen at the second carbon. Near the middle of the horizontal line is c 3 phosphate linkage while at the other end of the line is c 5 phosphate linkage fig. A nucleic acid containing deoxyribose is called deoxyribonucleic acid dna while that which contains ribose is called ribonucleic acid rna. Rna is a nucleic acid having almost similar structure as that of dna molecule except a uracil base instead of thymine. Jan 24, 2006 two dna binding and nick recognition modules in human dna ligase iii. Nucleic acids are the organic materials present in all organisms in the form of dna or rna.

Nucleic acid, naturally occurring chemical compound that is capable of being broken down to yield phosphoric acid, sugars, and organic bases. Segment of dna molecule that encodes a protein or rna, is referred to as a gene. Clearly, the structures of dna and rna are richer and more intricate than was at. Before a nucleoside can become part of a dna or rna molecule it must become complexed with a phosphate group to form a nucleotide either a deoxyribonucleotide or ribonucleotide. Importance of dnarna 3d structure nucleic acids are essential materials found in all living organisms. This information is stored in the form of long polymer chains. Rna oh opo5 ch2 base oh o 4 c 1 c h h h h 3 c 2 c oh 0h adenine guanine cytosine uracil 8 9. Dna deoxyribonucleic acid is the best known of all the molecules of life. Two dnabinding and nick recognition modules in human dna ligase iii. All these are essential in the normal functioning of the cell especially in protein synthesis. This chemical lability of rna, compared with dna, which does not have a reactive. The chemical structure of rna is very similar to that of dna, with two differencesa rna contains the sugar ribose while dna contains the slightly different sugar deoxyribose a type of ribose that lacks one oxygen atom, and b rna has the nucleobase uracil while dna contains thymine uracil and thymine have similar basepairing properties. Resistance of phosphate esters to basic hydrolysis.

The dna structure defines the basic genetic makeup of our body. The fourth base is thymine in dna and uracil in rna. Dna, rna, replication, translation, and transcription overview recall the central dogma of biology. Dna is organized into two strands by the pairing of bases a to t and g to c on complementary strands. Both dna and rna contain adenine, guanine and cytosine. However, a single rna molecule can, by complementary base pairing, form intrastrand double helixes, as in trna.

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. Journal of biological chemistry 2008, 283 16, 1076410772. Oh group in the same position on the sugar moiety deoxyribose. Feb 26, 2019 rna is a single stranded molecule containing a ribose sugar. Science high school biology molecular genetics rna and protein synthesis. It is a polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes. A brief introduction into dna and rna chemical structure is given. Each dna molecule in a cell is a long chain of repeating units called nucleotides, of which there are four types. Rna only has one strand, but like dna, is made up of nucleotides. What are molecular structure of sugar, base,nucleosides,nucleotides,dinucleotides, nucleic acid.

These rough equivalences were subsequently validated in the form of complementary base pairing in the watsoncrick dna structure. 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. Proteins within a cell have many functions, including building cellular structures and serving as enzyme catalysts for cellular chemical reactions that give cells their specific characteristics. Dna, rna, replication, translation, and transcription.