Concepts of Genetics (12th Edition)
12th Edition
ISBN: 9780134604718
Author: William S. Klug, Michael R. Cummings, Charlotte A. Spencer, Michael A. Palladino, Darrell Killian
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 16, Problem 1PDQ
HOW DO WE KNOW?
In this chapter, we focused on the regulation of gene expression in bacteria. Along the way, we found man opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanation given in the chapter, what answers would you propose to the following fundamental questions?
- (a) How do we know that bacteria regulate the expression of certain genes in response to the environment?
- (b) What evidence established that lactose serves as the inducer of a gene whose product is related to lactose
metabolism ? - (c) What led researchers to conclude that a repressor molecule regulates the lac operon?
- (d) How do we know that the lac repressor is a protein?
- (e) How do we know that the trp operon is a repressive control system, in contrast to the lac operon, which is an inducible control system?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Clary Fray used the pET vector system to express her prokaryotic amylase enzyme. She added
peptone into her culture broth of BL21(DE3) Escherichia coli strain to induce protein
expression. At the end of the experiment, she discovered that her protein was not expressed.
She repeated three more times but her protein of interest was still not produced.
(i)
(ii)
(iii)
(iv)
(v)
Explain the reason why Clary failed to obtain her protein of interest and suggest a
solution to troubleshoot this problem.
Clary plans to express her protein along with a polyhistidine-tag. Explain the
importance of His-tag in protein work.
Is DH5a Escherichia coli suitable to propagate the plasmid before protein expression?
Besides heat shock method, elaborate another procedure Clary could utilize to
transform the recombinant pET vector into the host cell.
If her supervisor instructs her to express a gene from gold fish (Carassius auratus), is
the expression system she is using now suitable for this experiment?…
A species of bacteria can synthesize the amino acid histidine, so they do not require histidine in their growth medium. A key enzyme, which we will call histidine synthetase, is necessary for histidine biosynthesis. When these bacteria are given histidine in their growth medium, they stop synthesizing histidine intracellularly. Based on this observation alone, propose three different regulatory mechanisms to explain why histidine biosynthesis ceases when histidine is in the growth medium. To explore this phenomenon further, you measure the amount of intracellular histidine synthetase protein when cells are grown in the presence and absence of histidine. In both conditions, the amount of this protein is identical. Which mechanism of regulation is consistent with this observation?
Scientists IPed a mutant version of KDM3A with
serine 264 altered to aspartic acid (dubbed S/D
mutation). They IPed S/D in cells that had not been
subjected to heat shock (HS-) or heat shock (HS+).
1) what is the purpose of mutating serine-264 to aspartic acid?
2) what conclusions can scientists make based on
results of lane5 and lane 6?
Chapter 16 Solutions
Concepts of Genetics (12th Edition)
Ch. 16 - Even though the lac Z, Y, and A structural genes...Ch. 16 - Predict the level of genetic activity of the lac...Ch. 16 - Prob. 1CSCh. 16 - Prob. 2CSCh. 16 - Prob. 3CSCh. 16 - HOW DO WE KNOW? In this chapter, we focused on the...Ch. 16 - Prob. 2PDQCh. 16 - Contrast positive versus negative control of gene...Ch. 16 - Contrast the role of the repressor in an inducible...Ch. 16 - For the lac genotypes shown in the following...
Ch. 16 - For the genotypes and conditions (lactose present...Ch. 16 - The locations of numerous lacI and lacIS mutations...Ch. 16 - Prob. 8PDQCh. 16 - Prob. 9PDQCh. 16 - Predict the effect on the inducibility of the lac...Ch. 16 - Erythritol, a natural sugar abundant in fruits and...Ch. 16 - Prob. 12PDQCh. 16 - Prob. 13PDQCh. 16 - Neelaredoxin is a 15-kDa protein that is a gene...Ch. 16 - The creation of milk products such as cheeses and...Ch. 16 - Both attenuation of the trp operon in E. coli and...Ch. 16 - Prob. 17PDQCh. 16 - Prob. 18ESPCh. 16 - In a theoretical operon, genes A, B, C, and D...Ch. 16 - A bacterial operon is responsible for the...Ch. 16 - A marine bacterium is isolated and shown to...Ch. 16 - Prob. 22ESPCh. 16 - Prob. 23ESP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Clary Leonhart used the pET vector system to express her prokaryotic amylase enzyme. She added peptone into her culture broth of BL21 (DE3) Escherichia coli strain. At the end of the experiment, she discovered that her protein was not expressed. She repeated three more times but her protein of interest was still not produced. (i) (ii) Explain the reason why Clary failed to obtain her protein of interest and suggest a solution to troubleshoot this problem. Clary plans to express her protein along with a polyhistidine-tag, or better known by its trademarked name IIis-tag. Explain the importance of His-tag in protein work.arrow_forwardConsider the mechanism of the enzyme RNase: What would happen to the Km (i.e., would it increase, decrease, or stay the same) if the his12 was mutated to a lysine? Explain. What would happen to the Kcat (i.e., would it increase, decrease, or stay the same) if the his12 was mutated to a valine? Explain.arrow_forwardIn the bacterium,Martian coli, it was discovered that the lac operon is positively regulated. Lactose, when present, binds to the regulatory protein A. The protein A-lactose complex then binds to the operator domain 0 and induces synthesis of lacZ+ and lacY+ MRNAS. a) What would be the most common phenotype of o- mutants in terms of lactose utilization? Explain your answer. b) What would be the most common phenotype of A- mutants? Explain your answer.arrow_forward
- Most of the mutations that Yanofsky recovered were missense mutations. However, Yanofsky also recovered a nonsense mutation that changed amino acid number 15 into a stop codon. This codon normally encodes Lysine. Does the recovery of this mutation support the hypothesis that this Lysine residue is critical in the function of the tryptophan synthetase protein? Why or why not?arrow_forwardThe lac genotypes are as shown below: P+OcZ-Y+A+// P¯O+Z+Y+A+ (i) The lac operon consists of three structural genes, lacZ, lacY and lacA. Which structural genes are involved in lactose metabolism? Explain. (ii) Draw and explain how lactose repress the gene expression in lac IS/I- heterozygote. (iii) What is the function of the promoter in the bacterial operon?arrow_forwardThe expression of genes in bacterial cells can be regulated on different levels in the production of the resulting protein.(a) Name the different levels of gene regulation in prokaryotes. (b) Discuss the different mechanisms used in each of these levels.arrow_forward
- The previously accepted model of the chloramphenicol action was that it inhibited all ribosomes equally. Why were the authors of the Marks, 2016 paper skeptical of this model? Choose all that are correct. Because they had observed that certain bacteria were resistant to chloramphenicol, and this proves that chloramphenicol stalls ribosomes at certain sites within those bacteria. Because certain MRNA templates had been observed to be inhibited by chloramphenicol more strongly than others Because chloramphenicol induces expression of chloramphenicol resistance proteins through translational arrest at specific codons in the leader ORFS of chloramphenicol resistance genes, which suggests there is preferential stalling at certain sites. Because chloramphenicol induces expression of chloramphenicol resistance proteins - therefore, these proteins must be able to be translated during chloramphenicol treatment. Because chloramphenicol binds the decoding center of the 30S subunit, and there are…arrow_forwardWhat would happen to the regulation of the tryptophan operon in bacterial cells that express a mutant form of the tryptophan repressor that (1) cannot bind to DNA, (2) cannot bind tryptophan, or (3) binds to DNA even in the absence of tryptophan?arrow_forwardSickle cell anemia is a widespread disease in many African countries and can be caused by a change in the amino acid sequence from glutamic acid to valine. A patient is diagnosed with the disease and a genetic fingerprint reveals the following DNA sequence for the gene: (a) (b) (c) (d) (e) Write down the mRNA sequence for the given DNA sense strand indicating the polarity. Derive the polypeptide from the mRNA molecule using the table of the genetic code (Table Q1 below) again indicating the polarity of the peptide chain. Indicate the position in the DNA molecule that could have caused the disease and write down all possible point mutations in the DNA sequence that could have caused it. [ The polypeptide chain is polymerized at the ribosomes using t-RNA molecules. Write down all possible t-RNA molecules with their anti-codons that are used to polymerize the amino acid VAL. Indicate the polarity. 3'-TAC TGA GCA AGA TTA CAT ACT-5' Explain what is meant by redundancy of the genetic code.…arrow_forward
- Messenger RNA molecules are very difficult to isolate in bacteria because they are rather quickly degraded in the cell. Can you suggest a reason why this occurs? Eukaryotic mRNAs are more stable and exist longer in the cell than do bacterial mRNAs. Is this an advantage or a disadvantage for a pancreatic cell making large quantities of insulin?arrow_forwardThe following DNA sequence has been determined from DNA isolated from a bit of prehistoric amber material (picture). It corresponds to a complete transcriptional unit without introns. Use the Genetic Code to predict the primary sequence of the polypeptide encoded by this preserved DNA. (Show relevant molecular intermediates, and provide detailed and appropriate labels)arrow_forwardCTP synthetase catalyzes the glutamine-dependent conversion of UTP to CTP. The enzyme is allosterically inhibited by the product, CTP. Mammalian cells defective in this allosteric inhibition are found to have a complex phenotype: They require thymidine in the growth medium, they have unbalanced nucleotide pools, and they have an elevated spontaneous mutation rate. Explain the likely basis for these observations.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education
Human Anatomy & Physiology (11th Edition)
Biology
ISBN:9780134580999
Author:Elaine N. Marieb, Katja N. Hoehn
Publisher:PEARSON
Biology 2e
Biology
ISBN:9781947172517
Author:Matthew Douglas, Jung Choi, Mary Ann Clark
Publisher:OpenStax
Anatomy & Physiology
Biology
ISBN:9781259398629
Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter
Publisher:Mcgraw Hill Education,
Molecular Biology of the Cell (Sixth Edition)
Biology
ISBN:9780815344322
Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter
Publisher:W. W. Norton & Company
Laboratory Manual For Human Anatomy & Physiology
Biology
ISBN:9781260159363
Author:Martin, Terry R., Prentice-craver, Cynthia
Publisher:McGraw-Hill Publishing Co.
Inquiry Into Life (16th Edition)
Biology
ISBN:9781260231700
Author:Sylvia S. Mader, Michael Windelspecht
Publisher:McGraw Hill Education
Bacterial Genomics and Metagenomics; Author: Quadram Institute;https://www.youtube.com/watch?v=_6IdVTAFXoU;License: Standard youtube license