SC.912.L16.3 DNA Replication
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You need to know the basic process of DNA replication and how it relates to the transmission and conservation of genetic information.
TUTORIALS
DNA replication by the Amoeba Sisters
DNA Replication 3-D
DNA Replication
EOC practice Questions
DNA and Its Structure
DNA (Deoxyrebonucleic acid) is a large molecule that directs how proteins will be assembled. DNA is a nucleic acid made up of nucleotides. Each nucleotide consists of a phosphate group, a 5 carbon sugar deoxyribose, and a nitrogenous base adenine, thymine, guanine and cytosine.
Base rule pair Adenine with Thymine and Guanine with Cytosine
DNA Replication occurs during S phase of interphase before cell division.
DNA replication results in two identical daughter molecules, each consisting of one old (original) strand and one newly-synthesized strand.
First, the two original strands separate. Then, DNA polymerases add complementary nucleotides to each strand. Because of the strictness of base-pairing rules the result is always the formation of two DNA molecules that are identical to the original DNA molecule.
Summary
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The two original DNA strands SEPARATE at the nucleotide bases to form two strands that serve as templates.
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RNA primer binds to template
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DNA polymerase ADDS complementary DNA nucleotides( An adenine (A)on one strand always pairs with a thymine (T) on the opposite strand, and a guanine (G)on one strand always pairs with a cytosine (C) on the opposite strand.
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DNA ligase seals the gaps between the Okazaki fragments
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TWO identical DNA daughter molecules, each consisting of one old (original) strand and one newly-synthesized strand.
One factor that stops DNA from being copies incorrectly is the nucleotides always match in the same way. Also, an enzyme DNA polymerase checks the arrangement of bases in the new DNA strand, decreasing the chance that DNA copy contains an error.