Restriction Enzymes : Recombinant Dna Essay

1459 Words May 6th, 2015 6 Pages
Restriction enzymes are used to manipulate DNA sequences to create recombinant DNA by first cutting up the foreign DNA in order to protect the bacteria cell against invading DNA from other organisms. The enzyme is very specific when it comes to identifying a specific DNA sequence. When the enzyme identifies the specific DNA sequence it cuts both DNA strands at specific points at the restriction site. Lastly, the DNA ligase joins the DNA from two different sources and produces a recombinant DNA molecule by catalyzing the formation of covalent bonds that close up the sugar-phosphate backbones.
Bacterial plasmids are used to clone DNA sequences of interest and then create bacterial strains which produce a human protein in large amounts by having restriction enzymes cut the specific gene from the human cell. The restriction enzyme must also cut the plasmid for the gene to be added into the plasmid and the plasmid to have room for the insertion of the gene. Next, the DNA fragments and the cut plasmids join by base-pairing between their complementary sticky ends, and then the DNA ligase is joined to complete the base-pairing. Through transformation the cells take up foreign DNA. The cell would replicate and produce exact copies of the recombinant plasmid in the offspring. Lastly, the recombinant plasmids in the offspring are used to replicate and produce human proteins in large amounts.
“DNA Library” describes the cDNA library and the genomic library.The genomic library is the…

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