--%>
Assignment Help - homework help

Structure of a DNA molecule

Elaborate the structure of a DNA molecule?

E

Expert

Verified

The molecule of a DNA is double-stranded. The molecule takes the shape of a double helix.
The DNA molecule has two complementary strands oriented in an anti-parallel fashion. All strand is made up of nucleotides. A nucleotide has a base (a purine or pyrimidine), a sugar (between the other two components) called deoxyribose, and a phosphate group. Nucleotides are connected to each other with phosphodiester bonds, creating a sugar-phosphate backbone to each strand.
Base of each nucleotide projects into an interior cavity of helix. Every base is opposite other base: adenine (a purine) is every time paired with the thymine (a pyrimidine), and the guanine (purine) with the cytosine (pyrimidine); this phenomenon is known as complementary base pairing.
Every nucleotide forms hydrogen bonds with its complementary base on another strand. Two hydrogen bonds form among adenine and thymine; three hydrogen bonds form between guanine and cytosine.

   Related Questions in Chemistry

  • Q : Adiabatic compression A lean natural

    A lean natural gas is available at 18oC and 65 bars and must be compressed for economical pipeline transportation. The gas is first adiabatically compressed to 200 bars and then isobarically (i.e. at constant pressure) cooled to 25°C. The gas, which is

    		•
  • Q : Entropy on molecular basis. The

    The equation S = k in W relates entropy to W, a measure of the number of different molecular level arrangements of the system.In the preceding developments it was unnecessary to attempt to reach any "explana

    		•
  • Q : What is Flash Photolysis Reactions.

    An example illustrates the type of mechanism that can be written to explain the development of flash photolysis reactions. Often, as the reactions in the ozone layer of the earth's atmosphere, we are interested in the kinetic behavior of species that are not a

    		•
  • Q : Polyhalogen compounds we need 10

    we need 10 examples for the polyhalogen compounds....please help me....need it urgently...

    		•
  • Q : What are Vander Waal's Radii? Vander

    Vander Waal's radii can be assigned to the atoms of molecules on the basis of the closeness of approach of these atoms in crystalline substances. Diffraction studies of crystals give information about hoe molecules can approach each other and can pack

    		•
  • Q : Mole fraction in vapours Choose the

    Choose the right answer from following. If two substances A and B have P0A P0B= 1:2 and have mole fraction in solution 1 : 2 then mole fraction of A in vapours: (a) 0.33 (b) 0.25 (c) 0.52 (d) 0.2

    		•
  • Q : How alkyl group reactions takes place?

    Halogenations: ethers react with chlorine and bromine to give substitution products. The extent of halogenations depends upon the conditions of reacti

    		•
  • Q : Concentration of an aqueous solution

    Give me answer of this question. The concentration of an aqueous solution of 0.01M CH3OH solution is very nearly equal to which of the following : (a) 0.01%CH3OH (b) 0.1%CH3OH (c) xCH3OH= 0.01 (d) 0.99MH2O (

    		•
  • Q : Question based on lowering of vapour

    Choose the right answer from following. The relative lowering of vapour pressure produced by dissolving 71.5 g of a substance in 1000 g of water is 0.00713. The molecular weight of the substance will be:  (a) 18.0 (b) 342 (c) 60 (d) 180

    		•
  • Q : Polyhalogen compounds introduction for

    introduction for polyhalogen compound

    		•