Question

Looking at the diagram of transcription in eukaryotes and using the information provided, how could the expression of lactase RNA be turned on and off by transcription factors, activators and repressors?

Styles Font Paragraph Activators bind to genes at Rapressors bind to genes seauences and at shaoser sequences and The expression of RNA in eukaryotes is initiated by the binding of basal transcription factors to the promoter sequence of a gene. This leads to the recruitment of RNA polymerase to sgnthesize an RNA transoript of the corresponding gene. uhancer increase transcription decrease transcription RNAtranscription can be increased or decreased additionally by binding of activator or repressor proteins to enhancer/ sitencer sequences which can be located far away from the promoter of the gene they are regulating - Transeription factors, activators and repressors bind DNA in a sequence specific fashion. This is achieved by chemical Enteractions (imostly hgdrogen bonds) between the piuino acts of the protein and the eases of the DNA molecinle to the

Answer 1

Ans:The lac operon of E. coli contains genes involved in lactose metabolism. It's expressed only when lactose is present and glucose is absent.Two regulators turn the operon on and off in response to lactose and glucose levels: the lac repressor and catabolite activator protein (CAP).The lac repressor acts as a lactose sensor. It normally blocks transcription of the operon, but stops acting as a repressor when lactose is present. The lac repressor senses lactose indirectly, through its isomer allolactose.Catabolite activator protein (CAP) acts as a glucose sensor. It activates transcription of the operon, but only when glucose levels are low. CAP senses glucose indirectly, through the hunger signal molecule cAMP.