8.3 DNA Replication VOCABULARY Replication The process by which DNA is copied during the cell cycle....
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Transcript of 8.3 DNA Replication VOCABULARY Replication The process by which DNA is copied during the cell cycle....
8.3 DNA Replication
VOCABULARYReplicationThe process by which DNA is copied during the cell cycle.
DNA PolymeraseAn enzyme that forms bonds between nucleotides during replication.
Semi-ConservativeEach DNA molecule contains an original strand of DNA and one new strand of DNA.
KEY CONCEPT DNA replication copies the genetic information of a cell.
MAIN IDEA
1.
2.
3.
8.3 DNA Replication
Replication copies the genetic information.
• A single strand of DNA serves as a template or a pattern for a new strand.
• The rules of base pairing directreplication. A=T C=G
• DNA is replicated during theS (synthesis) stage of thecell cycle.
• Each body cell gets acomplete set ofidentical DNA.
– EX: Your brain cells know how to make skin cells, but they don’t use this information.
8.3 DNA Replication
Proteins carry out the process of replication.
• DNA serves only as a template (pattern). • Enzymes and other proteins do the actual work of
replication.– Enzymes unzip the double helix
In both directions.
– Free-floating nucleotides form hydrogen bonds with the template strand.
nucleotide
The DNA molecule unzips in both
directions.
8.3 DNA Replication
– Polymerase enzymes form covalent bonds between nucleotides in the new strand.
– DNA polymerase enzymes bond the nucleotides together to form the double helix.
DNA polymerase
new strand nucleotide
8.3 DNA Replication
• DNA replication is semiconservative.
original strand new strand
Two molecules of DNA
• Two new molecules of DNA are formed, each with an original strand and a newly formed strand.
8.3 DNA Replication
There are many origins of replication in eukaryotic chromosomes.
• DNA replication starts at many points in eukaryotic chromosomes (it is faster and more efficient this way).
Replication is fast and accurate.
• DNA polymerases can find and correct errors.• If a part of the DNA is incorrect only that part is
repaired.