Chapter 16 - Recombinant DNA and biotechnology. In this chapter, students will be able to understand: How are large DNA molecules analyzed? What is recombinant DNA? How are new genes inserted into cells? What are the sources of DNA used in cloning? What other tools are used to manipulate DNA? What Is biotechnology? | Recombinant DNA and Biotechnology 16 Recombinant DNA and Biotechnology How Are Large DNA Molecules Analyzed? What Is Recombinant DNA? How Are New Genes Inserted into Cells? What Are the Sources of DNA Used in Cloning? What Other Tools Are Used to Manipulate DNA? What Is Biotechnology? How Are Large DNA Molecules Analyzed? Naturally occurring enzymes that cleave and repair DNA are used in the laboratory to manipulate and recombine DNA. How Are Large DNA Molecules Analyzed? Restriction enzymes (restriction endonucleases) cut double-stranded DNA into smaller pieces. Bacteria use these as defense against DNA from bacteriophage. DNA is cut between the 3′ hydroxyl group of one nucleotide and the 5′ phosphate group of the next—restriction digestion. Figure Bacteria Fight Invading Viruses with Restriction Enzymes How Are Large DNA Molecules Analyzed? There are many restriction enzymes that cut DNA at specific base sequences—the recognition sequence, or restriction site. How Are Large DNA Molecules Analyzed? Restriction enzymes do not cut bacteria’s own DNA because the recognition sequences are modified. Methylases add methyl groups after replication; makes sequence unrecognizable by restriction enzyme. How Are Large DNA Molecules Analyzed? Bacterial restriction enzymes can be isolated from cells. DNA from any organism will be cut wherever the recognition site occurs. EcoRI (from E. coli) cuts DNA at this sequence: How Are Large DNA Molecules Analyzed? The sequence is palindromic—it reads the same in both directions from the 5′ end. EcoRI occurs about once every four genes in prokaryotes. DNA can be chopped into small pieces containing a few genes. How Are Large DNA Molecules Analyzed? The EcoRI sequence does not occur anywhere in the genome of the phage T7. Thus it can survive in its host, E. coli. How Are Large DNA Molecules Analyzed? After DNA is cut, fragments of different sizes can be separated | Recombinant DNA and Biotechnology 16 Recombinant DNA and Biotechnology How Are Large DNA Molecules Analyzed? What Is Recombinant DNA? How Are New Genes Inserted into Cells? What Are the Sources of DNA Used in Cloning? What Other Tools Are Used to Manipulate DNA? What Is Biotechnology? How Are Large DNA Molecules Analyzed? Naturally occurring enzymes that cleave and repair DNA are used in the laboratory to manipulate and recombine DNA. How Are Large DNA Molecules Analyzed? Restriction enzymes (restriction endonucleases) cut double-stranded DNA into smaller pieces. Bacteria use these as defense against DNA from bacteriophage. DNA is cut between the 3′ hydroxyl group of one nucleotide and the 5′ phosphate group of the next—restriction digestion. Figure Bacteria Fight Invading Viruses with Restriction Enzymes How Are Large DNA Molecules Analyzed? There are many restriction enzymes that cut DNA at specific base sequences—the recognition .
