LIFESCI 3 Lecture Notes - Lecture 23: Wild Type, Allolactose, Flac
Document Summary
Pk transcription regulation: translation of transcription factors helps regulate transcription, transcription factors bind particular dna sequences, proximal promoter elements bind closer to/within promoter to regulate transcription. Repressor & activators: there are also positive and negative regulation of transcription factors that make them bind/fall off dna. Negative regulation of repressor -> positive regulation of transcription. Negative & positive controls mostly involve blocking rna pol from either the promoter or from physically moving/escaping promoter. If the repressor is there, will not get transcription. 3 main levels: completely off, basal level, high level: repressor bound to operator site of promoter -> off (blocking rna pol & preventing escaping/moving forward, activator transmit information telling rna pol to go. Co-repressor does something similar: blocks effect of upstream activation sequences. Beta-gal cleaves beta-glycosidic linkage connecting two sugar molecules. So lactose is a substrate for beta-gal: 2 fates: Get glucose from lactose & metabolize rest of the sugar.
