Download DNA Replication

SCIENCE STARTER #3 – 11/18/16
Find the other half of this DNA sequence:
A-A-G-T-C-T-G-C-A-T-G-T-A
There is 15% Adenine. Figure out the
percentages of the other nucleotides.
TAKE OUT YOUR DNA BOOKS
NOTES 5.2 –
DNA REPLICATION
Chapter 10
pg. 200-202
REPLICATION
 Purpose of Replication - Making copies of DNA
 Location - Nucleus
 Enzymes used: Helicase and DNA Polymerase
DNA
REPLICATION
STEP 1 – UNZIP DNA
 Helicase unzips DNA by
breaking the hydrogen
bonds between
nucleotides
 Replication Fork: point
where DNA strands
separate.
STEP 2 – ADD BASES
 DNA polymerase adds
complementary
nucleotides to the open
areas
 Nucleotides attach
from surrounding area
STEP 3 - FINISH
 Process continues until
entire strand is copied
 Result is two strands of DNA
 Semi-Conservative
Replication - Each strand is
50% new and 50% old DNA
ACCURACY AND REPAIR
 Copies must be 100% accurate
 Enzymes follow DNA polymerase, proofreading and
fixing errors
 Mutation= change in nucleotide at one location in
DNA
 Cancer: a mutation that has led to uncontrolled cell
reproduction
EXIT TICKET
 Eureka! You just found a way to figure out how much of each
nucleotide there is AND how to replicate DNA!
 Briefly describe what the complementary base pairing and
Chargaf f rules are.
 Briefly explain EACH step of DNA replication so the other
scientists can learn from you