10th AP Biology Lab - Restriction Enzyme Cleavage of DNA & Electrophoresis - Part 2
Questions:
Linear DNA fragments migrate at rates inversely proportional to the log1O of their molecular weights.
For simplicity’s sake, base-pair length is substituted for molecular weight.
a. How often would a restriction enzyme such as Not I, which has 8 nucleotides in its recognition sites
5’-GCGGCCGC-3’, cleave DNA on average?
(use the formula 4n, where n is the number of nucleotides in its recognition sites)
______________________________________
b. Would Not I cleave a species DNA more or less often if the DNA from that species were 70% A-T
rich? (remember to look at the bases making up Not I ‘s recognition site)
______________________________________
c. Predict the number of DNA fragments if Lambda bacteriophage DNA were incubated and cleaved
simultaneously with both Hind III and ECO RI (refer to the map below)
(Hint – extend the lines from both ECO RI and Hind III and count the spaces between them)
_______ bands would form
d. Predict the sizes of each of the DNA fragments formed from question c above, if Lambda
bacteriophage DNA were incubated and cleaved simultaneously with both Hind III and ECO RI - refer
to the map
below. (Hint – the first fragment will be the size of the first cut, for the others, you have
to
subtract the previous fragment from the later fragment to get the size.)