DNA structure - 3.2.2
• Our genes are on our chromosomes.
DNA replicates by using a single strand of the double helix to create a new copy.
The helix is 'unzipped' by an enzyme called DNA Helicase and becomes two separate, mononucleotide strands.
DNA Polymerase triggers the creation of new, 'daughter' strands.
• DNA is a very long polymer.
DNA is a very long polymer.
The basic shape is like a twisted ladder or zipper.
This is called a double helix.
One strand of DNA is a polymer of nucleotides.
One strand of DNA has many millions of nucleotides.
DNA has four different bases:
Cytosine C
Thymine T
Adenine A
Guanine G
Pyrimidines are single ring bases.
Purines are double ring bases. The Genetic Code DNA Anatomy - an interactive site DNA Replication - an interactive site
Thymine and Cytosine are pyrimidines - SINGLE RING
Adenine and Guanine are purines - DOUBLE RING