Introduction

• “The LAC operon” is “the operon” or gene group with a single promoter that can be transcribed as the single mRNA.
• The lactose acts like the inducer in the LAC operon because when it is provided to the medium then the activation process of the regulatory gene becomes possible.
• The LAC operon has the negative type of the control systems so it is a kind of the negative regulation.

SN: The LAC operon can be considered as the “group of genes” or the operon along with the single promoter. In the regulation process of the LAC operon the genes which present in the LAC operon are able to encode all the proteins because these have the ability to give the allowance to the bacteria in processing the lactose as the energy source. The LAC operon can  be considered as the “negative control system” as in the regulation process of this, the active LAC repressor typically blocks the expression which is able to turn off the transcription. So, it prevents the transcription while binding into the region of the operator. The lactose acts like the inducer in this operon because the activation process of the regulatory gene becomes possible only when it is provided into the medium.

Aim

• The main aim of this paper is to understand the whole regulation process of the LAC operon in a proper way.
• The aim of this paper is to properly find out the different activity of the β‐galactosidase, E.coli growth and the lactose to make this regulation process more active.
• Another aim of this paper is to find out the importance of this “regulation of the LAC operon”.

SN: The main aim of the paper of the regulation of “the LAC operon” is to understand the whole process of the regulation means how the lacs operon do the work as it contains different type genes like like the lacZ, lacY and lacA which are the different kind of work in the regulation process (Browning et al. 2019). The other aim of this paper is to find out the importance of this regulaiuton. It has the importance as the lacZ gene codes the β-galactosidase to cleave the lactose ion the glucose and galactose, lacY codes the necessary  transmembrane protein to “lactose uptake”. The “lacA codes” a transacetylase which transfers the “acetyl group”. There is also an aim of this paper which tries to find out the activity of the β‐galactosidase, E.coli growth and the lactose to make this regulation process more active.

Objective

• To understand the importance of the lactose at “the regulation of the LAC operon”.
• To understand “the comparative assays” about the “activity of the β‐galactosidase” in the “different media ” at “the regulation process of the LAC operon”.
• To understand “the comparative assays” about “the growth of the E.coli” at the “different media” in the regulation process of the LAC operon.

SN: There are some objectives of  this paper. These are to understand the importance or the work of lactose in the regulation of the LAC operon as it has the ability to encode all the necessary proteins because these are able to allow the bacteria to process the lactose as the energy source. The other objective of this paper is to understand the “comparative assays” to the activity of the β‐galactosidase in the regulation process of the LAC operon in the different media (Gordy et al. 2020). This paper also has an objective which is to understand the “comparative assays” to the growth of the “E.coli in the regulation process” of “the LAC operon” in different media. These objectives are able to understand the different processes of the regulation of the LAC operon to make it more advanced.

Four situation in “regulation of the LAC operon”

• “The existence of the glucose” and absence of the lactose are considered as a situation in the regulation of the “LAC operon”.
• A presence of a “glucose” and  the “lactose” are considered as a situation in the regulation of the “LAC operon”.
• An absence of both the “glucose and  the lactose” are capable of creating a situation in “the regulation of the LAC operon”.
• “The absence of the glucose” and “presence of the lactose” are considered the situation in “the regulation of the LAC operon”.

SN: The existence of the “glucose” and “absence of the lactose” can be capable of creating a situation where the E.coli can not be able to produce the β‐galactosidase “in the regulation of the LAC operon”. The “presence of the glucose and  the lactose” are able to create a situation where again the E.coli may not be able to produce the β‐galactosidase (Lankester et al. 2019). “The absence of both the glucose and the lactose” and “absence of the glucose” and presence of the lactose are the other two situations of the “regulation process of the LAC operon” where also the “E.coli” is not able to produce the “β‐galactosidase”.

Methods

• The LAC operon follows the method in the regulation process where the repressor protein is produced by the regulatory gene in lac 1.
• The lac 1 binds with the operator and lactose binds with the lac 1 to proceed the regulation.
• The  lac 1 is then left from the operator and RNA polymerase can bind in the promoter region and then the lactose goes to the operator to shut down the system which makes this method successful.

SN: The regulation of the LAC operon follows the method to do this regulation in the proper way. According to these methods the repressor protein is produced by the regulatory gene in lac 1. Then the lac 1 binds with the operator and lactose binds with the lac 1 where no protein is made in the regulation process and blocks the RNA polymerase (Phillips et al. 2019). After that RNA polymerase can bind in the promoter region and the lac 1 is left from the operator which transcribes the games in the mRNA. Then it translated into three proteins and lac 1 went back to the operator to shut down the process.

Results

• The measurement of the Cell density is done on the activity level of the β‐galactosidase.
• The result shows that both the cell density and activity of the β‐galactosidase are proportional to each other.
• The result indicates that in the absorbance of the 600nm, the cell density can be reached at the heist level of 0.261 while the β‐galactosidase activity level is 0.167.

Figure : Cell density – Absorbance

(Self created in MsXL)

SN: The measurement of the Cell density is done on the activity level of the β‐galactosidase to get the result which indicates that both the activity of the β‐galactosidase and the cell density  are proportional to each other (Velazco et al. 2021). From the plotting of the graph, it becomes clearer that in the absorbance of the 600nm, the cell density can be reached at the heist level of 0.261 while the β‐galactosidase activity level is 0.167. This result comes from the graph plotting according to the given values.

Conclusion

• There are three genes like lacZ, lac Y and lac A which control the regulation process of the LAC operon.
• The growth of the E.coli and activity level of the β‐galactosidase are able to improve the cell density for this regulation process.
• The result of the absorbance graph gives the understanding that both the cell density and the β‐galactosidase are related to each other in the regulation process.

SN: The the lacA codes the transacetylase which transfers the acetyl group, lacY codes the necessary  transmembrane protein to lactose uptake and lacZ gene codes the β-galactosidase to cleave the lactose ion the glucose and galactose. So, these are the main things to support the regulation process. The cell density can be increased by the activity level of the β‐galactosidase and growth of the E.coli. Both the cell density and the β‐galactosidase are related to each other in the regulation process which is clearly determined from the graph.