--%>
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 : Normality of sulphuric acid Help me to

    Help me to go through this problem. Normality of sulphuric acid is: (a) 2N (b) 4N (c) N/2 (d) N/4

    		•
  • Q : Relative lowering of the vapour pressure

    Choose the right answer from following.The relative lowering of the vapour pressure is equal to the ratio between the number of: (a) Solute moleules and solvent molecules (b) Solute molecules and the total molecules in the solution (c) Solvent molecules and the tota

    		•
  • Q : Procedure for separating the components

    Briefly describe the procedure for separating the components of the gun-powder?

    		•
  • Q : Mole 2.0gram of dolomite is heated to a

    2.0gram of dolomite is heated to a constant weight of 1.0g. Calculate the total volume of CO2 produced at STP by this reation

    		•
  • Q : Problem based on molecular weight

    Select the right answer of the question. Molecular weight of urea is 60. A solution of urea containing 6g urea in one litre is : (a)1 molar (b)1.5 molar (c) 0.1 molar (d) 0.01 molar

    		•
  • Q : Amount of glucose in blood What is the

    What is the normal amount of glucose in 100ml of blood (8–12 hrs after meal) is: (i) 8mg (ii) 80mg (iii) 200mg (iv) 800mg Choose the right answer from above.

    		•
  • Q : Means of molal solution Choose the

    Choose the right answer from following. A molal solution is one that contains one mole of a solute in: (a) 1000 gm of the solvent (b) One litre of the solvent (c) One litre of the solution (d) 22.4 litres of the solution

    		•
  • Q : What is solvent dielectric effect?

    Ionic dissociation depends on the dielectric constant of the solvent.The Arrhenius that ions are in aqueous solutions in equilibrium with parent molecular species allows many of the properties of ionic solutions to be understood. But difficulties began to

    		•
  • Q : Can protein act as the buffer Can

    Can protein act as the buffer? Briefly comment on that statement.

    		•
  • Q : Volumes of solution after concentration

    Hydrochloric acid solution A and B encompass concentration of 0.5N and 0.1N  corresspondingly. The volumes of solutions A and B needed to make 2liters of 0.2N of HCL are: (i) 0.5l of A + 1.5l of B (ii) 1.5l of A + 0.5 l of B  (iii) 1.0 l of A + 1.0l of B&nbs

    		•