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9 Cards in this Set
- Front
- Back
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Describe the structure of DNA. Explain the base-pairing rules and describe their
significance for DNA replication. |
1)double helix structure allows it to be easily replicated which is necessary to pass the genetic material from parent to daughter cells.
2)The base pairing rules involve only matching certain nitrogenous bases with other ones. The rules are that adenine pairs with thymine and cytosine pairs with guanine. |
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Describe the components of DNA including what comprises a nucleotide.
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DNA is a nucleic acid and the monomer of nucleic acids is the nucleotide. All
nucleotides are made of a 5 carbon sugar, phosphate group and a nitrogenous base. In DNA, the sugar is called deoxyribose. |
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Explain the role of DNA polymerases in replication. What are DNA polymerase’s
limitations? |
DNA polymerases are enzymes that help add new nucleotides to the growing
daughter strands of DNA. They also help in repairing nucleotide mistakes when mutations occur and replacing the RNA primers with DNA nucleotides. DNA polymerases can only add nucleotides to the 3’ end of the daughter strand. It can also only add nucleotides to a strand that is primed with a RNA primer. |
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Distinguish between the leading strand and the lagging strand. Define Okazaki
fragments. |
The leading strand is the daughter strand that is made continuously in the 5’ to 3’
direction as DNA polymerase adds new nucleotides to the 3’ end. The lagging strand can not be made continuously but instead short segments are primed with RNA primers and nucleotides added to the 3’ ends at various places along the template strand, forming Okazaki fragments. These fragments are later fused together with DNA ligase after the RNA primers are replaced with DNA nucleotides. |
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Enzyme that seals Okazaki fragments together. Also seals nicks
when nucleotide mistakes are removed and replacement nucleotides are brought it. |
DNA ligase
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Short stretch of RNA nucleotides that base pair with the template strand
of DNA to get the replication process started. |
Primer:
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Enzyme that makes the RNA primer
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Primase:
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Enzyme that helps unwind the double helix of the parental DNA to
allow for replication |
Helicase:
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Help the parental strands of DNA to stay
unwound and allow for replication |
Single
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