Concept explainers
To determine: Whether it is advantageous if the regulatory gene that codes for the tryptophan repressor is tightly linked to the trp operon.
Introduction: Gene regulation consists of many mechanisms that the cell uses to decrease or increase the production of certain gene products. The gene regulation in the bacteria mainly takes place in the level of transcription. In the eukaryotes, the gene regulation takes place in the level of transcription, post transcription, translation, and post translation.
To explain: The reason why there is no advantage if the regulatory gene that codes for the tryptophan repressor is tightly linked to the trp operon.
Introduction: Gene regulation consists of many mechanisms that the cell uses to decrease or increase the production of certain gene products. The gene regulation in the bacteria mainly takes place in the level of transcription. In the eukaryotes, the gene regulation takes place in the level of transcription, post transcription, translation, and post translation.
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Biology (MindTap Course List)
- INTERPRET DATA Develop a simple hypothesis that would explain the behavior of each of the following types of mutants in E. coli. Mutant a: The map position of this mutation is in the trp operon. The mutant cells are constitutive; that is, they produce all the enzymes coded for by the trp operon, even if large amounts of tryptophan are present in the growth medium. Mutant b: The map position of this mutation is in the trp operon. The mutant cells do not produce any enzymes coded for by the trp operon under any conditions. Mutant c: The map position of this mutation is some distance from the trp operon. The mutant cells are constitutive; that is, they produce all the enzymes coded for by the trp operon, even if the growth medium contains large amounts of tryptophan.arrow_forwardDescribe how the components of the trp operon system are affected by a mutation in trpC? Why is it that once enviornmental tryptophan is inserted into the cell, only the trp repressor is activated (turned on)?arrow_forwardDraw a schematic diagram showing the components involved in the regulation of the tryptophan operon.arrow_forward
- Under low tryptophanyl-tRNA (tRNAtrp), we expect the trp operon to be expressed because: Question 13 options: Sections 1 and 2 of the leader form a hairpin that acts as a transcriptional terminator. Sections 2 and 3 of the leader form a hairpin that prevents the formation of a transcriptional terminator. Sections 1 and 2 of the leader form a hairpin that prevents the formation of a transcriptional terminator. Sections 2 and 3 of the leader form a hairpin that acts as a transcriptional terminator. Sections 3 and 4 of the leader form a hairpin that acts as a transcriptional terminator.arrow_forwardWhich of the following statements about the trp operon is false? If a mutation in region 2 prevents the formation of the 2 + 3 loop in the 5’UTR transcription levels will increase. The trp operon is an example of negative repressible operon. Formation of the anti-terminator in the 5’UTR of the trp operon occurs when trp levels are low. In the presence of high trp-tRNA, the genes of the trp operon are not expressed. The role of trp is to bind to the repressor protein and activate it.arrow_forwardTryptophan (Trp) attenuation is an extra mechanism of regulation of trp operon when trp level is too high. Attenuation causes premature transcription termination. b) Predict what will happen if trp repressor lose its allosteric effect.arrow_forward
- Suppose that E. coli sustains a mutation in its gene for the lac operon repressor such that the repressor is ineffective. What effect would this have on the bacterium’s ability to catabolize lactose? Would the mutant strain have an advantage over wild-type cells? Explain your answer.arrow_forwardOne way that regulation is often studied is by examining the effects of mutations. For example, mutations within the parts of the lac operon have been well studied. Which of these mutants would be considered a constitutive mutant (the operon is always on)? a mutation in CAP that prevents the binding of CAMP a mutation in one of the structural genes that prevents the transport of lactose into the cell a mutation that disables the promoter for the operon a mutation that disables the repressorarrow_forwardWhat would happen if the operator sequence of the lac operon contained a mutation that prevented the repressor protein from binding the operator? (Explain what would happen both in the presence and absence of lactose)arrow_forward
- You are growing E. coli in a laboratory in order to study their operons. The growth media you are using contains lactose, no glucose and no tryptophan. Using your knowledge of operons and their regulation, answer the following questions Which operons would be functional under these conditions? 2. What repressors would be made? (NOTE: name the repressors using their gene names) 3.Which repressor(s) would be made in the inactive form? 4.Which repressor(s) would be made in the active form? 5.Which repressor(s) under these conditions can bind the operator sequence? 6.Which repressor(s)under these conditions cannot bind the operator sequence?arrow_forwardThe trp operon is a repressible operon. A strain of e coli develops a mutation whereby the trp repressor protein can no longer bind to the operator. How will this effect the production of tryptophan producing enzymes? Will these bacteria be able to live in a tryptophan free media (bacteria food)?arrow_forwardFor the trp operon, determine whether genes will be expressed (on) or silenced (off) given the following: a. Tryptophan levels are high. b. The trp repressor can no longer bind tryptophan.arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning