Structure of DNA:
In the nucleus DNA (Deoxyribonucleic acid) and RNA (Ribonucleic acid) are known. DNA and RNA are complex macro molecules and built up of millions of smaller units that are known as nucleotides. Therefore, DNA (Deoxyribonucleic acid) is a macromolecular substance along with double stranded polynucleotide.
Diagram: Watson and Crick model of DNA
Every nucleotide is formed of pentose sugar, a phosphate group and a nitrogenous base. Ribose in RNA is the constituent sugar and in DNA (Deoxyribonucleic acid) is the Deoxyribose. The nitrogenous bases are of 2 types:
1. purines and 2. pyrimidines.
Guanine and Adenine are the purines and cytosine and thymine are pyrimidines. The nitrogenous bases available in DNA (Deoxyribonucleic acid) are guanine, adenine, cytosine and thymine, while in RNA thymine is changed by uracil.The sub-unit comprising just only sugar and nitrogenous base is termed as nucleoside. A nucleoside combines along with phosphate to create a nucleotide.
So, four types of nucleotides are observed in DNA molecule. They are as follow:
1. Adenine nucleotide, 2. Guanine nucleotide, 3. Thymine nucleotide and 4. Cytosine nucleotide.
Therefore, nucleotides are building blocks of DNA.
In the year 1953, James Watson and Francis Crick planned double helix DNA (Deoxyribonucleic acid) model on the base of x-ray diffraction studies along with photographs of DNA (Deoxyribonucleic acid) taken through Wilkins and Franklin. DNA is a double stranded structure where the two strands are coiled around each other creating a double helix. The DNA (Deoxyribonucleic acid) duplex is “coil of life”. There are 2 grooves that found in DNA molecule they are major and minor grooves. The backbone of the helix is created of sugar and phosphate molecule. The bases of nitrogenous are connected to sugar molecules. The 2 nucleotide strands are held together through unstable hydrogen bonds. Erwin Chargaff in the year 1949 showed that:
(i) The bases pair in particular way. Adenine all the time pairs with thymine and guanine pairs with cytosine.(ii) Total amount of purine nucleotides is all the time equivalent to the total amount of pyrimidine nucleotides that is
[A] + [G] = [T] + [C].
(iii) The proportion of adenine is equivalent to thymine and thus also of guanine is equal to cytosine. But the [A] + [T] need not essentially be equal to [G] + [C].
These empirical rules concerning to the composition of bases in DNA is collectively termed as law of Chargaff or Base pair rules. There are 2 hydrogen bonds among the adenine and thymine (A= T) and there are 3 hydrogen bonds among the guanine and cytosine (G≡ C) pairing. The two strand run antiparallel in reverse directions that is they run in reverse direction 5’ to 3’ end and 3’ to 5’ end. The two strands are interwined in the direction of clock. The width of DNA (Deoxyribonucleic acid) molecule is 20 Å. The strand finished a turn every 34 Å along the length of it. There are ten nucleotides in every turn. The distance of internucleotide is 3.4 Å. Watson and Crick model of DNA (Deoxyribonucleic acid) is known as B-form DNA. The chains in B-form DNA are in right handed orientation.
Latest technology based Biology Online Tutoring Assistance
Tutors, at the www.tutorsglobe.com, take pledge to provide full satisfaction and assurance in Structure of DNA homework help via online tutoring. Students are getting 100% satisfaction by online tutors across the globe. Here you can get homework help for Structure of DNA, project ideas and tutorials. We provide email based Structure of DNA homework help. You can join us to ask queries 24x7 with live, experienced and qualified online tutors specialized in DNA as a Genetic Material. Through Online Tutoring, you would be able to complete your homework or assignments at your home. Tutors at the TutorsGlobe are committed to provide the best quality online tutoring assistance for Biology homework help and assignment help services. They use their experience, as they have solved thousands of the Biology assignments, which may help you to solve your complex issues of Structure of DNA. TutorsGlobe assure for the best quality compliance to your homework. Compromise with quality is not in our dictionary. If we feel that we are not able to provide the homework help as per the deadline or given instruction by the student, we refund the money of the student without any delay.
Monocotyledons and Dicotyledons tutorial all along with the key concepts of Number of cotyledons, Pollen structure, Number of flower parts, Leaf veins, Stem vascular arrangement and Root development
Alkaloids tutorial all along with the key concepts of Nomenclature, Isolation of Alkaloids, Properties, Chemical properties, Chemical Tests for Alkaloids, Pyrrolidine alkaloids, Pyrrolidine-pyridine alkaloids
The major aim of the income statement – or profit and loss account, because it is occasionally called – is to measure and report how much profit (wealth) the business has produced over a period.
The Mammalian liver tutorial all along with the key concepts of Functions of the Liver, Regulation of Sugar and lipids, Bile Production, Cholesterol regulation, Removal of Sex Hormones, Diseases of the Liver
TutorsGlobe.com Chemical Equilibrium-Applications Assignment Help-Homework Help by Online Access Chemistry Tutors
Viscosity tutorial all along with the key concepts of Velocity Gradient in Moving Fluids, Coefficient of Viscosity, Variationof with Temperature, Poiseuille's Formula, Stokes' Law and Terminal Velocity, Measuring by Falling Sphere
Theory and lecture notes of Systems of Linear Equations in Two Variables all along with the key concepts of Addition or Elimination, Graphical Interpretation of Solutions, nice problems, Regression Model and Linear Regression. Tutorsglobe offers homework help, assignment help and tutor’s assistance on Systems of Linear Equations in Two Variables.
Theory and lecture notes of Turing machine acceptors and decidability all along with the key concepts of turing machine acceptors and decidability, Turing Machines, Deterministic TM, Tape actions. Tutorsglobe offers homework help, assignment help and tutor’s assistance on Turing machine acceptors and decidability.
Theory and lecture notes of Parabolic PDEs-Explicit Method all along with the key concepts of differential equations, Boundary Conditions, Explicit Method Finite Differences, Heat Flow and Diffusion. Tutorsglobe offers homework help, assignment help and tutor’s assistance on Parabolic PDEs-Explicit Method.
tutorsglobe.com monetary policy aspects assignment help-homework help by online monetary policy of money tutors
Organogenesis and Formation of Germ Layers tutorial all along with the key concepts of Orgauogenesis in animal, Product of Three Germ Layer, Formation of germ layers, Formation of early nervous system-neural groove, tube and notochord and Somitogenesis
The Operational Amplifier tutorial all along with the key concepts of Basic OP-AMP, Single-Ended Input, Double-Ended (Differential) Input, Double-Ended Output, Common-Mode Operation, Common-Mode Rejection, Differential Inputs, Opposite Polarity Inputs, Same Polarity Inputs, Non-Inverting Amplifier, Unity Follower
tutorsglobe.com photorespiration assignment help-homework help by online plant physiology tutors
chemical kinetic-rates of reactions tutorial all along with the key concepts of rate of a chemical reaction, monitoring the rates of chemical reactions, nature of the reactant, concentration of the reactant, factors that affect reaction rates
Classification and Characteristics of Organisms tutorial all along with the key concepts of Taxonomic Hierarchy, The Super Kingdoms, The Viruses, Eukaryotae and Five Kingdoms.
1944172
Questions Asked
3689
Tutors
1469265
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!