Biology 1202B Lecture Notes - Lecture 14: Lac Repressor, Trp Operon, Lac Operon
14 Jul 2016
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Document Summary
All cells have the same complement of dna. Yet, cells of different types are vastly different. Differences are not a result of different dna. Different expression of the same set of genes. Differences are a result of regulation of gene expression (primarily transcription) Tend to be single celled and relatively simple. Manufacture the simple products needed for (brief) survival and reproduction. Depending on what is available they turn on/off various biochemical pathways. Cluster of genes and the dna sequences involved in their regulation. Glucose is preferred sugar (turned on when glucose not available but lactose is) Short sequences that is a binding sequence for a regulatory protein. Repressor when bound to the dna, reduces the likelihood that genes will be transcribed. Activator when bound to the dna, increases the likelihood that genes will be transcribed. Lac repressor binds operator most of the time. Negative control when it binds to the operator, it represses the expression of the gene.
