1. DNA & The Genetic Code
The sequence (order) of bases in a strand of DNA acts as a template for DNA replication and makes the code for building proteins
The genetic code is a “triplet” code meaning that every three nitrogen bases codes for one amino acid
A gene is the entire sequence of bases that codes for a specific protein
Like a recipe for a specific dish

2. Replication of the DNA
Replication is the copying of DNA:
Two strands separate and form the replication fork
Free-floating nucleotides match up with the nucleotides on each strand
Two identical molecules of DNA are made
This process is semiconservative

3. Replication of the DNA The principal enzyme is DNA polymerase
DNA replication is carried out by enzymes:
The principal enzyme is DNA polymerase
DNA polymerase joins individual nucleotides to form DNA molecules
This enzyme also proofreads the new strands – maximizes the odds that each new strand is a perfect copy

4. Check for Understanding:
Describe the three steps of DNA replication
Two strands separate and form the replication fork
Free-floating nucleotides match up with the nucleotides on each strand
Two identical molecules of DNA are made
What are the four bases and how do they pair together?
Adenine pairs with Thymine
Cytosine pairs with Guanine
Describe what is meant by a “triplet code.”
Three bases code for one amino acid