1. DNA Replication, Transcription
and Translation
Turning genes into proteins

2. DNA Replication
DNA replication
– Takes place in the nucleus
– Requires 2 enzymes
Purpose- to make copies of DNA
How is DNA replication related to mitosis?

3. Complimentary Base Pairing
• The 2 sides of DNA are not
exactly the same, they are
complimentary.
• If on one side of the DNA strand
there is the nucleotide
Cytosine, the opposite side will
have Guanine, Adenine always
pairs with Thymine.
• Remember Chargaff’s rule!

4. DNA Replication
DNA is replicated through…
1) The unwinding of DNA’s
double helix.
2) Separation of strands by
helicase
3) Formation of new
complementary strands by
DNA polymerase.

5. helicase
Step 1- an Step 2- enzyme DNA There are now 2 new
polymerase adds DNA molecules each
enzyme, helicase, op with an original
complimentary base
ens up the original pairs to the original parent strand.
DNA molecule. parent strand.

6. Replication Review
• Where does replication take place?
• What are the enzymes involved and what do they
do during replication?
• What is a gene?
• Approximately how many genes do you have?
• How is DNA replication related to mitosis?
• Explain complimentary base pairing. Which
scientist helped to prove this? (hint: there is a rule named after him)