RESULTS
The hypothesis is that as the amount of lactose increases in a treatment, the higher the enzyme production and activity. A total of six treatments were done in order to determine whether the amount of lactose in a substance correlates with the amount and production of b-galactosidase.
Experiment 1: The use of OD600 as an indicator of bacterial population size. In addition, the use of Abs 420 as an indicator of protein production. Then the Miller units of each treatment was determined to indicate not only protein activity, but also bacterial population size. In experiment 1, OD600 is used to help show the bacterial population size in each treatment. Six different treatments were compared to one another. …show more content…
This can be seen because the tubes that contain only the lactose showed higher enzyme activity and bacterial population size as observed from the Abs420 and OD600. In a lac operon system, a repressor molecule binds to DNA, which prevents gene expression by blocking transcription essentially turning the gene off. However, lactose can bind to the repressor molecule and remove it, so it would start transcription. This system only occurs if glucose is not available as an energy source, but lactose is. Essentially, the entire purpose of this system is to use b-galactosidase to break down lactose into glucose and galactosidase and use glucose as the energy source. In an absence of lactose, the enzyme would be able to break down the glucose, but it will be at a slower rate due to the large size of the molecule compared to lactose. This can be seen in tube 4, which contained both glucose and lactose. The enzyme activity in tube 4 was not as high as tube 2 and 3, which contained only lactose. This is because the enzyme will take a longer time because the cell will not waste its energy breaking down lactose and will just start using the glucose instead since it is already