BIO206H5 Lecture Notes - Lecture 17: Catabolite Activator Protein, Regulatory Sequence, Repressor
Document Summary
The lac operon: an example of prokaryotic transcriptional regulation. Lac i, lac z, lacy & laca (proteins) Lac is involved in the metabolism of a sugar called lactose. Changes in gene expression allow bacterial cells to respond to environmental change. Very little control over its environment so it needs to be able to sense that environment and respond to the environment it is in; does not have ability to move from environment; Migration and immigration are important for gene regulation for animals. Positive control: regulatory protein (ac*tivator) binds to dna -> increases transcription rate; it increases the ability of the rna pol to bind to the promoter and transcribe the gene; binds and enables. Negative control: a regulatory protein (repressor) must be released from dna before rna pol can bind and transcription can occur; binds and prevents. When genes are controlled by an activator (inducible)
