DNA
DNA molecules are large and complex. They carry the genetic code that determines the characteristics of a living organism.
The backbone of the DNA double helix consists of alternating phosphate and deoxyribose sugar molecules.
Interlinking bases hold the two sides together.
Four different bases exist in DNA:
- A = adenine
- T = thymine
- C = cytosine
- G = guanine
As A is complementary to T and C is complementary to G they pair up.
This is known as the base-pairing rule.
A nucleotide consists of 1 phosphate, 1 sugar and 1 base.
Each individual's DNA is unique.
Apart from identical twins, no one shares the same sequence of bases.