Question

2. Maltose operon/regulon a. What does signal detect/respond to? b. When is Signal On/OFF C. Inducable or Repressable system? Or mixed? d. Describe the system's response

Answer 1

Solution

a) maltose is signal for operon thatwhy operon responce to the presence or absence of maltose in cell.it is inducer molecule to start operon.

b)when maltose is present then it activates RNA polymerase to start transcription of operon genes required for maltose metabolism. As maltose is completely used in cell so concentration get lowered at that time operon gets off.

c) maltose operon is a type of inducible operon because presence of maltose leads to starting on of the operon.

d) system responce

system respond to maltose both way in the presence and absence of maltose.

the maltodextrans are absorbed inside cell..but to start metabolism of maltodextran there is need of its enzyme. Such enzymes are present on malt operon.so in the presence of maltose operon get on to start breakdown of maltose.

as maltose is completely broken down that time operon is off.because there is no need to start operon for maltose metabolism beacuse there is no maltose remained for metabolism.

Maltose operon regulation (positive) Activator mal binding site Promoter male malf | malg DDD MOLMMD MMD No transcription RNA polymerase (Absence of inducer - maltose) Maltose activator protein (a) Activator mal binding site Promoter male malf malg Dm DDD DDD RNA - - -Transcription polymerase proceeds Maltose activator protein Inducer (maltose)