What is the link?

E – Describe the process of genetic engineeringC – Explain the advantages and disadvantages and interpret dataA – Evaluate the technology

Objectives

The tools of gene technology

• Restriction endonucleases – allow DNA to be cut

• Reverse transcriptase – copies DNA

• DNA ligase – rejoins DNA

Recombinant DNA

DNA Ligase Restriction endonuclease

Sticky ends

Inserting genes• Plasmids can be cut open with restriction

endonucleases• If a gene is cut out with the same enzyme

they will have complementary sticky ends• DNA ligase seals up the gap in between by

forming a phosphodiester bond

How do you know if a cell has been transformed?

• Radioactive probe– Complementary to DNA– DNA hybridises with the probe– Those cells are selected and grown up

to obtain a pure culture of those cells

• Antibiotic resistance– Cells which have taken up the plasmid

will grow on the medium

Agricultural:•Flavr savr tomato ripens slower•Golden Rice produces more vitamin A

Applications

Industrial:•Enzymes produced cheaply in large amounts (chymosin)

Medical:•Hormones (growth hormone, insulin)

Conversion of mRNA to cDNA, using reverse transcriptase.

• Activity:– Now that you know the

correct sequence complete the cut and stick worksheet to put the synthesis of cDNA into the correct order

– Add any extra details about the process which is occurring

Conversion of mRNA to cDNA, using reverse transcriptase.

• Activity:– Now that you know the

correct sequence complete the cut and stick worksheet to put the synthesis of cDNA into the correct order

– Add any extra details about the process which is occurring

cDNA• cDNA is DNA formed from an mRNA

template using reverse transcriptase– Requirements are:

• primers• dNTPs• Reverse transcriptase• DNA polymerase

• Reverse transcriptase works first followed by DNA polymerase

• (RNAase can be used to digest unwanted RNA)

Reverse Transcriptase

mRNA cDNA

Four basic reagents are needed to produce cDNA: mRNA as template, dNTPs, reverse transcriptase and

primers.

Owner of a biotechnology company

Environmental activist

Government official responsible for issuing public announcements on the technology

Archbishop of Canterbury responsible for the moral decisions of 60% of the UK.

Less pesticides need to be used for resistant crops.

Hormones can be produced that will not be rejected when put in to humans

Not that different from selective breeding but less inbreeding necessaryNo idea what

will happen when new genomes are released into the environmentNo one knows

the health risks of GM foods

Flavr savr tomatoes do not require chemicals to stop ripening. Better for health?

Multinationals think they are God creating and patenting life

No one has the right to mess with teleos

Genetic “mistakes” are made on purposeIs this paving the way to eugenics, selectively breeding humans

E – Describe the process of genetic engineeringD – Explain the advantages and disadvantagesC – Evaluate the technology

Objectives