BIO230H1 Lecture 2: Lecture 2 Readings
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BIO230H1 Full Course Notes
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Document Summary
Gene expression can be regulated at many steps in the pathway from dna to rna to protein. Gene regulatory proteins were discovered using bacterial genetics. Gene regulatory proteins: protein that binds to a specific dna sequence to influence the transcription of a gene. Lambda repressor is a regulator encoded by bacteriophage lambda (a virus). It shuts off the viral genes that code for protein components of new virus particles, enables the viral genome to remain a silent passenger in bacterial chromosome, multiplying with bacterium when conditions are favorable for bacterial growth. Lac repressor turns off production of proteins responsible for lactose metabolism when this sugar is absent from the medium. The tryptophan repressor is a simple switch that turns genes on and off in bacteria. Operon: a group of contiguous genes that are transcribed into a single mrna molecule. Operator: short region of dna in a bacterial chromosome that controls the transcription of an adjacent gene.
