In the following points, I have summarized Lac operon in Ecoli. I need to check if this is on the right track? and where does 'cleavage of disaccharides' fit into this picture?
Lactose is a disaccharide and the bacteria need specific genes to manage catabolism
1) The lacl promotor gene synthesis the repressor protein which binds to the operator gene stopping the RNA polymerase from coding the lac operon genes
2)But when lactose is present, it needs the specific genes to catabolise lactose
3) So, When allolactose (a derivative of lactose)is present, it binds to the repressor protein, the repressor releases from the operator gene
4) This allows the RNA polymerase can attach to the DNA control region
5) And drive down the operon for transcription and induction of the enzyme lacZ(beta-galactosidase) lacY and lacA which breaks lactose down into glucose and galactose
6) When the lactose is all gone, the repressor returns to the operator in a feedback loop system
In the following points, I have summarized Lac operon in Ecoli. I need to check if this is on the right track? and where does 'cleavage of disaccharides' fit into this picture?
Lactose is a disaccharide and the bacteria need specific genes to manage catabolism
1) The lacl promotor gene synthesis the repressor protein which binds to the operator gene stopping the RNA polymerase from coding the lac operon genes
2)But when lactose is present, it needs the specific genes to catabolise lactose
3) So, When allolactose (a derivative of lactose)is present, it binds to the repressor protein, the repressor releases from the operator gene
4) This allows the RNA polymerase can attach to the DNA control region
5) And drive down the operon for transcription and induction of the enzyme lacZ(beta-galactosidase) lacY and lacA which breaks lactose down into glucose and galactose
6) When the lactose is all gone, the repressor returns to the operator in a feedback loop system
Related textbook solutions
Related questions
1. The lac operon of E. coli controls the expression of genes that code for enzymes involved in lactose metabolism. The operon system is inducible in that it can be âturned onâ by the presence of lactose. Mutations to various regions of the lac operon have been discovered which affect both the control of gene expression and the function of the gene products.
These mutations include:
I - = produces a repressor protein that can not bind to the operator region
I s = produces a repressor protein that can not be removed from the operator region
O C = can not bind a repressor protein
Z - = produces a defective (non-functioning) β-galactosidase enzyme
( I- are recessive to I+; I+ recessive to IS )
Detail the functionality of the lac
operon under the following genetic and cellular conditions.
| GENES | Lactose present | Repressed (yes/no) | Constitutive (yes/no) | Inducible (yes/no) |
| I + O + Z + | no | |||
| I + O C Z + | no | |||
| I S O + Z + | yes | |||
| I - O + Z + | yes | |||
| I S O C Z + | no |
