9.4 Genetic Engineering Updates: Mutations practice due Homework: –Read 9.5 –Restriction enzymes cut sites/gel due tomorrow Unit 5 quiz 2 Thursday Keystone Biology Exam: 5/15, 5/18

9.4 Genetic Engineering Keystone Question of the Day: Which of the following best describes the function of an enzyme? –A) lowers the activation energy barrier –B) decreases the reaction rate –C) increases the activation energy barrier –D) maintains homeostasis for cells

9.4 Genetic Engineering Timber Rattlesnake Crotalus horridus Size: inches in length Status: Candidate Species Habitat: Upland forest with rocky outcroppings, talus slops, rock crevices, rock ledges with vegetation, mature forest with numerous fallen logs, young forest with predominant leaf litter cover.

9.4 Genetic Engineering Which of the following mutations changes the type of amino acid during translation? A) missense B) nonsense C) silent D) all Which of the following mutations can result in a new stop codon? A) point B) substitution C) indel (frameshift) D) all Which of the following mutations creates a variation in a gene, but no change in a protein? A) missense B) nonsense C) silent D) all

9.4 Genetic Engineering How is DNA used in genetic engineering? Activator: Identify the type of mutation and its effect on translation. Original DNA: TAA TAG TAG AAA CCA CAA AGG Mutated DNA: TAA TAG AAA CCA CAA AGG Key terms – restriction enzyme, gel electrophoresis, transgenic, genetically modified organism, gene therapy,

9.4 Genetic Engineering Biotechnology relies on cutting DNA at specific places. Restriction enzymes cut DNA: –Found in bacteria –“molecular scissors” –site specific

9.4 Genetic Engineering –some cut straight across and leave “blunt ends” –some make staggered cuts and leave “sticky ends”

9.4 Genetic Engineering

A restriction map uses gel electrophoresis to separate fragments of DNA Bands represent size fragments

9.4 Genetic Engineering Genetic engineering produces organisms with new traits. A transgenic organism has genetic material another organism inserted into its genome using a plasmid

9.4 Genetic Engineering Transgenic organisms can be produced and cloned –gene inserted into plasmid –plasmid inserted into bacteria –bacteria express the gene

9.4 Genetic Engineering Transgenic plants are common in agriculture. –transgenic bacteria infect a plant –plant expresses foreign gene (pesticide resistance)

9.4 Genetic Engineering Gene therapy could replace defective or missing genes, or adds new genes, to treat a disease.

9.4 Genetic Engineering Summary:

9.4 Genetic Engineering New genes can be added to an organism’s DNA. Genetic engineering involves changing an organism’s DNA to give it new traits. Genetic engineering is based on the use of recombinant DNA. Recombinant DNA contains genes from more than one organism. (bacterial DNA)

9.4 Genetic Engineering Transgenic animals are used to study diseases and gene functions. –transgenic mice used to study development and disease –gene knockout mice used to study gene function

9.4 Genetic Engineering Several experimental techniques are used for gene therapy. –genetically engineered viruses used to “infect” a patient’s cells –insert gene to stimulate immune system to attack cancer cells –insert “suicide” genes into cancer cells that activate a drug

9.4 Genetic Engineering Gene therapy has many technical challenges. –inserting gene into correct cells –controlling gene expression –determining effect on other genes

9.4 Genetic Engineering Genetic screening can detect genetic disorders. Genetic screening involves the testing of DNA. –determines risk of having or passing on a genetic disorder –used to detect specific genes or proteins –can detect some genes related to an increased risk of cancer –can detect some genes known to cause genetic disorders DMDN

9.4 Genetic Engineering Restriction enzymes have several applications. Generating recombinant DNA using plasmids Characterizing genes - electrophoresis Comparing mutations – restriction map –SNPs – single nucleotide polymorphisms

9.4 Genetic Engineering Mammals can be cloned through a process called nuclear transfer. –nucleus is removed from an egg cell –nucleus of a cell from the animal to be cloned is implanted in the egg

9.4 Genetic Engineering Entire organisms can be cloned. A clone is a genetically identical copy of a gene or of an organism.