U1: 2- Structure And Replication Of DNA Flashcards
To which carbon attachment points do bases and phosphates attach in a DNA nucleotide?
Carbon 1 and carbon 5
What name is given to the backbone of a DNA strand formed from deoxyribose sugar and phosphate?
Sugar-phosphate backbone
What type of bonds form between bases on two complimentary strands?
Hydrogen bonds
What term is used to describe the fact that the two strands of DNA run in opposite directions to each other?
Antiparallel
Name the two ends of one DNA strand?
3’ and 5’ ends
What name is given to the arrangement of the two strands of DNA?
Double helix
What name is given to the strand that is found on the left hand side on a DNA strand that runs from 3’ to 5’?
Leading strand
What name is given to the short sequence of nucleotides that attach to the 3’ end of the parental strand about to be replicated?
Primer
What name is given to the enzyme needed to replicate the strands during DNA replication?
DNA polymerase
How is the replication of the leading strand described because it is replicated without any interruptions?
Continuous
What name is given to the strand opposite the leading strand?
Lagging strand
How is replication of the lagging strand described because it is replicated in fragments?
Discontinuous
Name the enzyme needed to join the fragments together in the lagging strand
Ligase
Name 5 requirements of DNA replication
- DNA template strand
- ATP
- DNA nucleotides
- primers
- enzymes (DNA polymerase and ligase)
What name is given to the technique that can be used to create many copies of a piece of DNA outside of the body?
Polymerase chain reaction (PCR)
What word is used to describe the fact that you are making multiple copies of a piece of DNA in a PCR?
Amplification
Describe the first stage of PCR
Heat the DNA strand to 92-98°C to break the hydrogen bonds and separate the strands
The next stage of PCR after heating involves cooling the DNA down to between 50-65°C. Why does the DNA have to be cooled?
So that primers can attach
Lastly the DNA is heated to 70-80°C to allow an enzyme to replicate the strand. Name the enzyme involved.
Heat-tolerant DNA polymerase
Name three uses of amplified DNA produced through PCR
- forensic (crime scene investigation)
- medical (genetic disorder diagnosis)
- paternity disputes