Question

here is the diagram

ecause there is no repressor protein attached to the operator, what enzyme con attach to the promoter and move past the operator to transcribe the structural genes? Color this enzyme pink "color the repressor gene purple and the repressor protein it codes for red. Examine the shape of the repressor protein. 45) Is it an active or inactiverepressor protein? The diagram below shows the trp operon when turned off." Repressor gene Promoter Operator Structural genes DNA Trpe TPD Trpc Tp B Trp . mRNA !! Protein WE Active Inactive - Repressor Repressor O Protein Tryptophan (co-repressor) "Color the structural genes blue, the repressor gene purple, the promoter green, the operator yellow and the repressor protein red. 46) In order for the operon to be turned off," what must attach to the operator? Notice that the molecule tryptophan is shown in the diagram. Normally, tryptophan is used by the cell as quickly as it is produced Occasionally, however, excess tryptophan builds up or the cell may take in extra tryptophan from its environment Color all the molecules of tryptophan shown in the diagram above brown. (Hint: There are three.) 47) If there is excess tryptophon in the cell, would it be efficient to have the trp operon turned "on" resulting in even more tryptophan being synthesized? Notice that excess tryptophan molecules attach to the inactive repressor protein 48) How does this change the shape of the repressor protein? Tryptophan is acting as a co-repressor in this operon All repressible operons are turned "off" by the attachment of a co-repressor molecule to an inactive repressor protein, causing it to become active. Note that the activated repressor protein can attach to the operator. 49) Is the operon now turned "on" or "off"? *Color RNA polymerase pink 50) Can RNA polymerase move past the operator in order to transcribe the structural genes? 202

Answer 1

46.In order to tirn off ,tryptophan (co-represssor )and aporepressor complex should bind with operator.

47.Never ,if tryprophan exceeds, it will combine with aporepressor to bind with the operator ,hence it chechks the transcription and translation.Hence it is turned off.

50.Never ,RNA polymerase can't move across the operator due to active repressor protein.