U.1 KA.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 in two complimentary strands?
Weak hydrogen bonds
What term is used to describe the fact that the two strands of DNA run in opposite directions?
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 stranded 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
- DNA polymerase
- Ligase
What name is given to the technique that can be used to create many copies of a piece of DNA outside 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 PCR?
Amplification
Describe the first stage of PCR.
Heat the DNA strand to between 92 and 98 degrees 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 and 65 degrees. Why does the DNA have to be cooled?
So that primers can attach
Lastly the DNA is heated to between 70 and 80 degrees to allow an enzyme to replicate the strand. Name the enzyme.
Heat -tolerant DNA polymerase
Name three uses of amplified DNA produced through PCR.
- Forensic testing
- Paternity disputes
- Genetic disorder diagnosis
