Β-Galactosidase Lab Report

This lab was designed to study the generation of β-Galactosidase over a 2 lab period, so it got 2 sections; first part was to measure the levels β-galactosidase produced in E.coli K12 cells specifically using IPTG a molecular biology reagent to determine the time of induction of the lac operon. The second part of this experiment was to observe the effects of alternative inducing agents, glucose and antibiotic addition on the induction of β-galactosidase in E.coli K12; this experiments goal was to detect the effect of alternate induction agents, antibiotic and glucose adding on to inducing of β-galactosidase in E.coli. The β-galactosidase is normally switched off in E.coli except in the presence of lactose; the enzyme β-galactosidase breaks down lactose into galactose and glucose. (Matthews 2005). The lac operon or lactose operon is essential for the transportation of lactose in E.coli. In the lac operon three structural genes, z, y and a genes, are transcribed into an mRNA molecule that synthesizes 3 proteins. The lac I gene is a protein produced by the regulatory gene.

Bacteria requires to adjust to their environment and to consume any metabolic fuels that can be accessible for their survival; the best favored would be glucose. If it happens that there is a lack or deficit of the glucose, bacteria cells must acclimate to utilizing another form of sugar lactose. This can be achieved by changing the absorptions of some proteins. Lac repressor can bind to major groove of lac operon which results in inhibiting the transcription of mRNA for Lac proteins; this is the case when there is no lactose present. When lactose is available the protein allo-lactose goes to bind to lac operon that able it to change in shape of lac repressor, consequently it will not be able to bind to the lac operon, this is called