The Structure of DNA
The 'backbone' of a DNA molecule is made up
of only two groups. One is a ribose sugar
(that is one with 5 carbon atoms in it), called deoxyribose
and the other is a phosphate
These alternate and form a long chain.
Sticking out from the backbone is the third
group found in DNA. These are the organic bases.
There are four bases :
A (Adenine), C
( Cytosine), G (Guanine)
and T (Thymine)
Adenine always pairs with thymine.
Cytosine always pairs with guanine.
A to T and C to G