What is the nitrogenous base that bonds with DNA?

DNA contains four kinds of nitrogenous base: adenine (A), thymine (T), guanine (G) and cytosine (C).

The DNA molecule is a double helix. It consists of two strands of smaller molecules called nucleotides wrapped around each other.

Each nucleotide is itself made of three components. These are a sugar (deoxyribose), a phosphate group and one of the four nitrogenous bases.

EAch strand in the DNA double helix consists of a 'backbone' of alternating sugar and phosphate groups with a nitrogenous base attached to each sugar. The bases in the two strands project towards each other and the strands are held together weak electrical bonds (called hydrogen bonds) between the bases.

The bases in the two strands always form specific base pairs. This means that an adenine in one strand always binds to a thymine in the other strand. Similarly, a guanine in one strand always binds to a cytosine in the other strand.

The bases consist of rings of carbon and nitrogen atoms. Thymine and cytosine have a single ring and are called pyrimidines. Adenine and guanine have a double ring and are called purines.

This double helix structure of DNA was discovered by James Watson and Francis Crick in 1953, marking the beginning of the age of molecular biology. Their proposal of a double helix was partly based on data supplied by Rosalind Franklin, who thought at the time that attempts to build models of DNA structure were premature.. For more detail of Franklin's contrribution see http://en.wikipedia.org/wiki/Rosalind_Franklin.

For more information see:
http://learn.genetics.utah.edu/units/basics/see right there you reaaaly dont need all that ok.