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14 Cards in this Set
- Front
- Back
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Explain Semi-conservative Replication |
describes the mechanism by which DNA is replicated in all known cells. This mechanism of replication was one of three models originally proposed for DNA replication: Semiconservative replication would produce two copies that each contained one of the original strands and one new strand. |
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On which side of each DNA strand are new nucleotides added? (Fig. 12.4) |
We always add them to the 3’ site. |
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Describe the difference between the leading and the lagging strand. |
Leading Strand: runs 5’ to 3’, runs right to left Lagging Strand: has to go the other way sometimes they have to copy and then start over again and then go and start over yet again whereas the leading strand is continuous. It goes to where they last left off with the copying of the DNA Lagging Strand: has to go the other way sometimes they have to copy and then start over again and then go and start over yet again whereas the leading strand is continuous. It goes to where they last left off with the copying of the DNA DNA Polymerase: adding new nucleotides |
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Why is an RNA primer made and how is it replaced? |
Small section of RNA bases made by RNA polymerase. DNA polymerase cannot add nucleotides unless there is an already existing nucleotide there. DNA polymerase replaces the RNA primer with DNA.DNA Ligase: fill in the gaps between the okazaki fragments |
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What does DNA polymerase do, and how are replication mistakes fixed? |
DNA polymerase adds new bases They can go in and take it out and put in the right one. |
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What unwinds the DNA and keeps it unwound? |
Helicase unwinds the DNA Single-stranded binding proteins or SSBP’s keep it open Topoisomerase II relieves the stress of unwinding |
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Describe an origin of replication and a replication bubble. |
Replication: where you start opening up your DNA Replication Bubble: (eukaryotic DNA- they have multiple origins) you have a leading strand and a lagging strand on the same strand of DNA. Prokaryotes the DNA is circular and we have one origin. DNA is not very long and it’s circular so they just go around. |
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What does telomerase do? Why is this significant? |
An enzyme that will add in bases that we have lost on the telomeres. It only does it in your reproductive cells, stem cells, and germ cells. |
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What does PCR stand for, and what is its purpose? |
Polymerase Chain Reaction; to make millions of copies of DNA. |
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What is gel electrophoresis, and what is the point of it? |
separates the resulting DNA fragments according to their size (in kb or thousands of base parts) |
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What are restriction enzymes used for? |
Restriction enzymes cut DNA at certain sequences. Like a pair of scissors that cuts your DNA in specific places. |
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What is the point of Southern Blotting? |
After you separate a DNA on a gel then you transfer everything on that gel to paper. Then you stain that paper with antibodies (proteins that will bond with specific things) then it will light up. Purpose- if we are looking at one specific gene. |
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Explain the idea behind DNA sequencing. |
the process of determining the precise order of nucleotides within a DNA molecule. It includes any method or technology that is used to determine the order of the four bases (based on size)—adenine, guanine, cytosine, and thymine—in a strand of DNA. |
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What is recombinant DNA, and how is used to make GMOs (genetically modified organisms)? |
DNA recombined from one source to another source. You can cut out pieces of human DNA and put it into a piece of bacteria that can now make human proteins. |
