How might the regulation of the lac operon change if a point mutation occurred that blocks the ability of the repressor protein (LacI) to bind lactose?
Q: 10. a. Describe an operon? b. How lac operons controls gene expression in bacteria
A: (a) An operon is a functional unit of DNA containing a set of genes including structural gene, a…
Q: 1) The logic of the Lac operon was deciphered by using bacterial lac-operon mutants. Crucial to the…
A: Lac operon is a genetic unit in bacteria that helps in the metabolism of lactose in E.coli and lac…
Q: Assuming that the level of glucose is low, a mutation in the repressor associated with the lac…
A: The lac operon stands for lactose operon. These are a set of genes that are found in E.coli and…
Q: Name and describe two types of constitutive mutants of the lactose operon.
A: Operon can be defined as an operating unit, which is nothing but gene clusters that are located…
Q: Operons are a common feature of bacterial genomes. Which of the following statements about the lac…
A: Lac operon has three important genes that helps the bacteria to take up the lactose sugar when…
Q: 1.True or false: In a bacterial species with a "lac operon", the repressor protein will be bound to…
A: Prokaryotic gene regulatory system is known as operon system. In this process the expression of…
Q: How does induction control enzyme synthesis using lactose operon? 2. Describe how level of a key…
A: By controlling the transcription of the mRNA which is needed for the enzyme synthesis, the genetic…
Q: 1. Complete the following table based on your lac operon simulations. Absence of lactose Presence of…
A: An operon is a group of genes that are transcribed at the same time. The lac operon consists of…
Q: 1. Explain why catabolite repression is used in regulating the lac operon and describe how it…
A: Repression by glucose of beta-galactosidase synthesis is spontaneously reversible in all strains of…
Q: 1. Explain the functioning and regulation of the following operons: lac, trp. 2. Explain the…
A: Every organism have various charcyerstics why may or may not be similiar to each individual. Tgese…
Q: 4a. The diagram below represents (a) the lac operon in the OFF state and (b) lac operon in the ON…
A: Note - Since you have asked multiple questions, we will solve the first question for you. If you…
Q: 5. Regulation of bacterial operons by inducers, e.g. lactose, exhibits which of the following…
A: The regulation of gene expression can occur at the level of transcription and translation.
Q: 10. Modify the diagrams below to reflect the activation and repression of lac operon. Use arrows,…
A: The prokaryotic gene regulatory system is known as operon system in which the expression of…
Q: Considering the fec operon described above, under which conditions would the operon be off? Choose…
A: The protein synthesis process is started from the operon region that is actually worked as a switch.…
Q: 1. Lac and Trp Operon are two different processes of sugar and amino acid. Describe the differences…
A: Lac and Trp operon are found in E. coli and other bacteria.
Q: 1 Given the following genotypes, explain how the mutation (identified by a () superscript will…
A: Operon is a unit consisting of one or more systems that function coordinately under the control of…
Q: 1. A. A mutation in E. coli is found that fails to induce the arabinose operon. Upon further…
A: A mutation is a change to the DNA sequence of a cell. This change can be due to rearrangements on…
Q: 4. Predict the level of genetic activity of the lac operon as well as the status of the lac…
A: In lac operon, structural genes responsible for lactose metabolism are all under the control of a…
Q: 10. Modify the diagrams below to reflect the activation and repression of lac operon. Use arrows,…
A: Lac operon contains genes involved in metabolism. The genes are expressed only when lactose is…
Q: The gad operon is controlled by a number of transcription factors that regulate a promoter of…
A: Bacteria re found in prokaryotes. They are more primitive as compared to eukaryotes.
Q: 1d regulation of the lack operon by the lack repressor is an example of negative regulation. what in…
A: E.coli bacterium intake glucose as a primary source of energy metabolism . When a glucose is scarce…
Q: 1) The UR operon which is composed of sequences A, B, C, and D (which may or may not be genes of…
A: An operon may be considered as a group of certain genes which function together so as to regulate…
Q: 2. Assume you have identified a new operon in bacteria (which you call the suc operon) that encodes…
A: The gene expression in prokaryotes is under the control of operon system in which the transcription…
Q: 5. Briefly describe the lac operon and how it controls the metabolism of lactose.
A: An operon is a group of genes that are expressed under the same regulatory sequences.
Q: Think about the situation where there is an increased concentration of both glucose and allolactose…
A: Lacoperon is an operon that consists of a group of genes in E.coli which is required for the…
Q: Strain LOLZ has a mutation in the lacI gene that results in a lacI protein that cannot bind…
A: Lac operon is the segment of DNA which is responsible for breaking down lactose into glucose and…
Q: Provide the SIGNIFICANT differences between the following
A: The process by which a cell regulates the conversion of DNA to RNA (transcription) and hence…
Q: 1. Predict the effect of each situation on the Lac or Trp operon. Lac operon is ON Lac operon is OFF…
A: Operon is the group of genes that are expressed under the same regulatory sequences.
Q: 4. A mutant strain of E. coli produces B-galactosidase in the presence and the absence of lactose.…
A: An operon is defined as a set of structural genes regulated by a common promoter in bacteria.
Q: 2. You are studying the regulation of the lactose operon in Escherichia coli, by measuring…
A: The lac operon is responsible for the entry and metabolism of lactose in E. coli as well as most…
Q: 1. A strain of E. coli is genetically engineered in which the lacZ and lacY removed and replaced…
A: Operon acts as a single regulated unit having one or more structural gene, promoter gene, a…
Q: (iii) Mark all sentences as true or false. (A) RNA polymerase binds to the operator sequence of the…
A: RNA polymerase is defined as the enzyme that catalyzes the transcription of DNA into RNA. It is a…
Q: 6. Which of the following is true about E. coll's lac operon? If there is no lactose present, the…
A: Option 1. For the lactose transport and metabolism of in E. coli and other bacteria, the lac operon…
Q: A bacterial cell undergoes a change and the two Trp codons of the tryptophan leader sequence are…
A: Tryptophan operon is an example of repressible operon which remain transcriptionally active and…
Q: I. Answer the following: 1. What are the main elements of the lac operon and their functions? 2.…
A: Definition:- An operon is a group of genes that are transcribed at the same time. These are a…
Q: The lac operon has which of the following characteristics? O 1) usually requires an activator…
A: In Eukaryotes all genes are separate and produce individual mRNAs on transcription. However, in…
Q: Suppose you have an E. coli in which the gene that codes for the lac repressor protein has been…
A: Lac operon is an inducible type of operon that involves the breakdown of lactose in E.coli. The lac…
Q: If a researcher moves the operator to the far end of the operon, which of the following processes…
A: An operator is a genetic sequence that helps the DNA sequence to attach proteins in charge for…
Q: (iii) What is the function of the promoter in the bacterial operon?
A: The lactose operon (also abbreviated as the lac operon) is a group of genes present in E. coli and…
Q: Provide the SIGNIFICANT differences between the following: 1. Operon Systems Inducer/Lac…
A: An operon is a cluster of functional genes which are regulated by the common operator. Operons…
Q: 9. A single base substitution mutation in lacY gene of the Lac operon would render the entire lac…
A: Gene regulation at the level of transcription in bacteria is achieved by the operon model. Operon is…
Q: In the txp operon, a repressor protein acquires a mutation such that it cannot bind to tryptophan.…
A: BASIC INFORMATION TRYPTOPHAN OPERON This system is known as Repressible Operon System. It can also…
Q: 2. Assume you have identified a new operon in bacteria (which you call the suc operon) that encodes…
A: Gene expression in prokaryotes is under the control of an operon system in which the transcription…
Q: Which will be bound to the Lac Operon in an environment with lactose and glucose? A) both repressor…
A: The bacteria comprise many operons and one of the important operons is lac operon. Lac operon is…
Q: Please tell me: What's a mutation in moleculer terms? 2. When a mutation deletes a base in genomic…
A: DNA DNA content specific sequence of nitrogenous base in their stand. If the sequence is changed…
Q: 1) A. What is the difference between a repressible vs, an inducible operon? B. Using diagrams…
A: The answer is given below
Q: 3.1 Which of the following is NOT true about the lac operon? I) The lac operon is use to help…
A: ANSWER;- B) is NOT true about the lac operon. Allolactose binds to the repressor so they can bind…
Q: What are the effects of the following conditions on Lac operon of bacteria
A: Lac Operon is a set of three structural genes regulated by a common promoter and maintain lactose…
3. How might the regulation of the lac operon change if a point mutation occurred that blocks the ability of the repressor protein (LacI) to bind lactose?
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- 1. Draw a diagram of the lac operon. PO I+P+O+Z+Y+ I+P+OcZ+Y- I-P+O+Z+Y+ Lab section (circle): lacz gene lac Y gene lacA gene I+P+O+ZY/IPO+Z+Y- 2. The promoter (P) is the start site of transcription through the binding of RNA polymerase before actual mRNA production. Mutated promoters (P) cannot bind RNA polymerase, so no mRNA is made. In the table below, make predictions about the expression of ß-galactosidase and permease for different partial diploid (F') genotypes. Do this for E. coli growth on two different types of media - one without lactose, and one with. Use a to mark where there is no enzyme produced, and a + to mark where the enzyme is made. The first genotype has all wild-type alleles, and has been filled in as an example. Genotype IPOCZ+Y/I-P+O+Z-Y+ ISP+O+Z+Y/I+P+O+Z*Y* CR 1:00 Lactose absent B-galactosidase Permease R 3:-00 + R 6:30 Lactose present B-galactosidase F 10:00 Permease5. Regulation of bacterial operons by inducers, e.g. lactose, exhibits which of the following properties? Inducer effect on RNA polymerase binding to the promoter Inducer binds to the Repressor produced by: repressor and: Activates the repressor A. Activates the repressor A separate gene Genes of the operon A separate gene Genes of the operon A separate gene Enhances В. Enhances Activates the repressor D. Inhibits the repressor Inhibits the repressor С. Inhibits inhibits Е. No effect 6. Gene transcription rates and mRNA levels were determined for an enzyme that is induced by a newly developed drug. Compared with untreated levels, drug treatment caused a 10x increase in the gene transcription rate and a 20× increase in both mRNA levels and enzyme activity. These data indicate that a primary effect of the drug treatment is to decrease which one of the following? A. The activity of RNA polymerase B. The ability of miRNA to act on mRNA C. The rate of translation D. The rate of binding of…4. What are the effects of the following conditions on Lac operon of bacteria?A)Glucose is absent and lactose is presentB)Glucose is present and lactose is presentC) Glucose is present and lactose is absent
- 4. Predict the level of genetic activity of the lac operon as well as the status of the lac repressor and the CAP protein under the cellular conditions listed in the following table (+ = sugar present; = sugar absent): Cellular conditions Lactose Glucose + + + + a) Operon (on or off or basal?) b) Operon (on or off or basal?) Lac repressor (bound to operator?) CAP protein (bound to CAP site?) d) Operon (on or off or basal?) PROE Lac repressor (bound to operator?) CAP protein (bound to CAP site?) c) Operon (on or off or basal?) Lac repressor (bound to operator?) CAP protein (bound to CAP site?) Lac repressor (bound to operator?) CAP protein (bound to CAP site?)2. Assume you have identified a new operon in bacteria (which you call the suc operon) that encodes enzymes required for catabolism of the sugar sucrose. The structural genes that are required to breakdown sucrose are transcribed from a promoter (Psuc). One of these enzymes is encoded by the sucS gene. Expression of the operon is controlled by a regulator, called SucR, which binds to an operator (O). Using your knowledge of the lac operon, interpret the results of the following experiments (Table 1) to propose a model describing how the sucrose operon might be regulated. Cell genotype Production of SucS enzyme Without sucrose With sucrose R* O* P* s* R O* p* s* ++ R* O P* S* -- RO* p* s* / R* Oʻ p* 5 R° O* p* S ++ -- ++ ++ Table 1. Production of SucS enzyme in various strains. “-" in the cell genotype indicates a loss of function mutation, “+" indicates wild type function, two genotypes separated by a / indicate a merodiploid or partial diploid. R° is a mutant version of SucR that…3. Draw an anabolic operon with three biosynthetic genes for compound Q and a catabolic operon with two catabolic genes for compound R. Draw the operons in the repressed state --Include these components: Promoter, RNA polymerase, Operator, Repressor, Inducer or Corepressor, Biosynthesis genes or Catabolic genes. -- Indicate whether [Q] or [R] is low or high for each operon when it is repressed, and explain your reasoning. FYI: [NaCl] is read as the concentration of NaCl.
- 5. There are four genes in the FAK operon. a. How many mRNAs are encoded by this operon? b. The FAK operon has a weak promoter, where RNA polymerase does not bind well. What type of molecule could directly help RNA polymerase to bind more tightly to this promoter? i. An inducer 6. Consider the Lac operon of E. coli, which is normally expressed only when lactose is present and glucose absent. You identify a mutant strain of bacteria in which Lacz, Lacy, and LacA, are expressed in the absence of glucose, whether or not lactose is present. a. ii. An activator iii. A promoter iv. A repressor v. A ligand C. Assume that one mutation causes this mis-regulation. Which interaction must be disrupted by this mutation? i. Interaction between RNA polymerase and the lac promoter ii. Interaction between Lacl protein and the lac operator (its binding site) Interaction between CRP and CAMP Interaction between CRP-CAMP (aka CAP) its binding site adjacent to lac operon Interaction between Lacl protein…5. Use the table below to describe under what conditions the lac operator is turned on and off. Is the lac operon ON/OFF? Condition: No lactose HIGH lactose & HIGH glucose (i.e., high ATP, low cAMP) HIGH lactose & LOW glucose (i.e. low ATP, high CAMP) What is regulating the lac operon to be ON or OFF?1. Assuming that the level of glucose is low, a mutation in the repressor associated with the lac operon of E. coli which prevents binding of the repressor to lactose should result in: a. constitutive expression of the lac operon genes b. lack of expression or refuced expression of the lac operon genes under all circumstances c. expression of the genes only when lactose is present d. expression of the genes only when lactose is absent e. lack of expression of the lac operon genes, resulting in an increase in lactose production
- 1. A. A mutation in E. coli is found that fails to induce the arabinose operon. Upon further investigation, it is found that this mutant also is unable to induce the lac operon. Which of the following single mutations could explain this phenotype (you may choose one or more answers a) Mutation in the promoter of the ara operon b) Mutation in the promoter of the lac operon c) Mutation in the operator of the lac operon d) Mutation in the AraC protein for the ara operon e) Mutation in the repressor of the lac operon f) Mutation in the Y gene for Lac permease g) Mutation in the gene for adenylate cyclase h) Mutation in the gene for CAP (or CRP) protein i) Mutation in the gene for rho factor j) None of the above B. Briefly explain the reasons for your choice(s)28. Which statement does NOT explain why the lac operon would not be effectively regulated by an attenuation mechanism like the trp operon? 1.Lactose is a substrate for the lac operon protein products. 2.Products of lac operon enzymes are not used in protein synthesis. 3.Transcription and translation do not happen simultaneously for the lac operon. 4.Attenuation is a suitable regulatory mechanism for anabolic amino acid pathways. 5.All of these statements explain why regulation by attenuation would not be effective for the lac operon.3. Which of the following is NOT true about the lac operon? I) The lac operon is use to help breakdown lactose II) The lac operon is deemed as a "leaky" operon due to its promoter III) Allolactose binds to the repressor so they can bind to the operator together IV) lacI gene and the lacZ gene are under the control of the same promoter A) I and II B) III C) IV D) III and IV E) I and III
