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Transposon. “Jumping Genes” DNA Sequence that moves from one location to another Insertion Sequence “retro” – made with transcriptase (like virsuses). Transposon. Direct repeats. Composite. Adds extra genes between two insertions. Regulation of Metabolic Pathway. Regulate genes
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Transposon • “Jumping Genes” • DNA Sequence that moves from one location to another • Insertion Sequence • “retro” – made with transcriptase (like virsuses)
Transposon • Direct repeats
Composite • Adds extra genes between two insertions
Regulation of Metabolic Pathway • Regulate genes • Regulates enzymes
Operons • A unit of genetic material that functions in bacteria and phages • Clustered gene with one promoter • On/off switch
Negative Gene Regulation • Repressible operons • Transcription is inhibited • Inducible operons • Transcription is stimulated
The trp Operon • Corepressor – absent makes tryptophan
Repressor • Corepressor – present stops tryptophan production • Corepressor – helper for repressor
lac operon • Lactose absent / repressor active – operon off
lac operon • Lactose present / repressor inactive – operon on • inducer
Positive Gene Regulation • cAMP • Accumulates when glucose is scarce
Nucleosome • DNA and histone proteins together
Gene Amplification • Not passed to children • Embryos – ribosome production • Cancer cells – drug resistance
Questions??? • Gene loss?? • Gene rearrangement?? • Genome??
Transcription Factors • A protein that binds to DNA and allows for RNA polymerase to attach and begin transcription • Enhancers – bends DNA to allow the factors to be closer to the promoter region
RNA Splicing • Allows alternative mRNA molecules to be built – ex. exons will act as introns
Proteasome • A giant protein complex that destroys proteins tagged for elimination by ubiquitin.
DNA Testing • PCR • RFLP
Practical Application • Diagnosis of Diseases • Human Gene Therapy • DNA Fingerprinting • Environmental Uses • Agricultural Uses
Safety and Ethical Questions • Pages 407-408 or 399