BIOL 222 Lecture Notes - Lecture 26: Repressor, Lactose Permease, Lac Operon
10 Nov 2016
School
Department
Course
Professor
Document Summary
Homework #6 due monday: group homework, will be second to last homework. Parts of the lac operon: laci, lacz, lacy, laca. Laci = repressor protien, constitutively expressed at low levels. Lacz = breaks down lactose glucose and galactose, and lactose allolactose. Lacy = lactose permease (latose transporter): transports lactose into the cell, laci is a repressor protein that can bind to the promotor, abs site. Promotor region = lac promoter = lacp. Two ways the lac operon is regulated: 1. lac operon is inducible and regulated via negative control. When allolactose is on, there should be transcription: 2. lac operon is also inducible and regulated via positive control. More in-depth: if only lactose is present, e. coli turns on lac operon and uses lactose, if both lactose and glucose are present, e. coli uses glucose rst, then lactose (diauxic growth).
