Thinking Like a Scientist Handout 3A
DNA and Restriction Enzyme Scenario
Congratulations! Through careful research your team has discovered a
procedure for joining two pieces of DNA from different organisms. First
you use a restriction enzyme to cut apart a fragment of DNA. This enzyme
recognizes a specific sequence of bases in the DNA molecule, and cuts the
molecule within that sequence. The result is a set of double-stranded DNA
fragments with single-stranded ends called sticky ends. The sticky ends
will form base pairs with complementary single-stranded stretches on other
molecules. By combining cut DNA from different sources that have complementary
sticky ends, modified DNA fragments are formed.
Even though you can make new DNA, you're not sure that the molecule will
function in the same way as normal DNA. Your modified DNA molecules are
not useful unless they can be made to replicate and function within a cell.
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