First 140 words of the document:
DNA must be copied before the nucleus and then the cell divide.
Requirements for Replication
The double stranded DNA has to act as a TEMPLATE
There needs to be a mixture of the nucleotides to COMPLEMENTARY BINDto the DNA
DNA polymerase CATALYSES the addition of complementary bases
ATP provides ENERGY to drive the process.
DNA Replication Fork
This is the model for semi-conservative replication
1. The DNA HELICASE enzymes break the hydrogen bonds between the bases of the
complementary nitrogenous bases
2. The double helix seperates into 2 strands and unwinds (with the help of DNA GYRASE )
3. DNA POLYMERASE catalyses the addition of nucleotides by complementary base pairing
to form a new polynucleotide chain
4. DNA LIGASE joins small sections of the DNA together.