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Warm-up. List 3 new things you learned about bacteria. Genetic engineering. Recombinant DNA technology. Why are we using bacteria for biotechnology rather than some other organsism?. What are some characteristics that make bacteria a good choice for genetic engineering?
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Warm-up • List 3 new things you learned about bacteria.
Genetic engineering Recombinant DNA technology
Why are we using bacteria for biotechnology rather than some other organsism? • What are some characteristics that make bacteria a good choice for genetic engineering? (think and then talk with your partner)
Bacterial plasmids Most bacterial DNA is on a single large chromosome, but some DNA is in small circles called plasmids. • Plasmids can have genes which make bacteria resistant to antibiotics • Plasmids can be passed between bacteria
Plasmids can be manipulated easily in the laboratory • Plasmids can be collected from bacteria • Restriction enzymes can cut specific sequences of DNA • Ligase (enzyme) can paste pieces of DNA together • Bacteria can be transformed by taking in plasmids given to them
Cutting and Pasting DNA • Restriction enzymes act like molecular scissors – they cut the DNA! • Ligaseacts like molecular glue – it is used to reconnect the DNA that has been cut by restriction enzymes.
GATCC G G CCTAG A Restriction Enzyme: BamH I
Transforming Bacteria • When a bacterial cell takes in a plasmid from the environment, it has new DNA (and therefore, new traits). • Scientists say that the bacteria has been transformed.
Exit PowerPoint and open files in Internet Explorer: • Gene engineering cartoon.swf • Gene engineering video.swf
How to produce human insulin from bacteria • Isolate plasmid DNA from bacteria and insulin gene from human. • Cut both DNAs with the same restriction enzyme. • Mix the DNA together with ligase. • Insert the new DNA into bacteria (transformation). • Use antibiotics to kill any bacteria without the plasmid. • Grow bacteria and harvest the insulin.
How to produce human insulin from bacteria • Isolate plasmid DNA from bacteria and insulin gene from human. • Cut both DNAs with the same restriction enzyme. • Mix the DNA together with ligase. • Insert the new DNA into bacteria (transformation). • Use antibiotics to kill any bacteria without the plasmid. • Grow bacteria and harvest the insulin.
Read in book (Owl) p. 239-242. • Draw a diagram showing the six steps to introduce a foreign gene into bacteria.