EBK CONCEPTS OF GENETICS
12th Edition
ISBN: 9780134818979
Author: Killian
Publisher: YUZU
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 16, Problem 2PDQ
Summary Introduction
To write: An essay on the evolution of the regulatory system in bacteria and genes related to common functions that are found together in operons.
Introduction: Gene regulation contains various mechanisms that helps the cells to regulate the expression of a particular gene product. The regulation of gene expression in bacteria has been evolved to perform some specific functions.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A number of mutations affect the expression of the lac operon in E. coli. The
genotypes of several E. coli strains are shown below. ("+" indicates a wild-type gene
with normal function and "-" indicates a loss-of-function allele.) Please predict which
of the following strains would have the lowest beta-galactosidase enzyme activity,
when grown in the lactose medium.
Orpt o* z* r*
Orpt ot z* Y
OrptoztY
Orrotzr
OrPotz*Y
For the following questions, describe the expression levels of the structural genes in the Trp operon under the conditions described.
In the absence of tryptophan, the structural genes will:[ Select ] ["No longer be expressed", "Be constantly expressed", "Be deleted from the operon"]
In the presence of tryptophan, the structural genes will:[ Select ] ["No longer be expressed", "Be constantly expressed", "Be deleted from the operon"]
In the absence of tryptophan and the promoter sequence was mutated such that the RNA polymerase can no longer bind, the structural genes will:[ Select ] ["No longer be expressed", "Be constantly expressed", "Be deleted from the operon"]
In the presence of tryptophan and the promoter sequence was mutated such that the RNA polymerase can no longer bind, the structural genes will:[ Select ] ["No longer be expressed", "Be constantly expressed", "Be deleted from the operon"]
In the absence of tryptophan and the trpR repressor gene is mutated such that the…
Supply the words “off" or “on" in the blanks below:
In an inducible operon, transcription is normally
and must be turned
In a repressible operon, transcription is normally
and must be turned
Briefly describe the overall function of the structural genes in the lac operon.
Briefly describe the overall function of the structural genes in the trp operon.
For the following descriptions of the bacterial lac operon, determine if lactose is present
(P) or absent (A).
The repressor is bound to the operator.
The repressor is inactive.
RNA polymerase transcribes the structural genes.
Allolactose is bound to the repressor
For the following descriptions of the bacterial trp operon, determine if tryptophan levels
are high (H) or low (L).
The repressor is bound to the operator.
The repressor is inactive.
RNA polymerase transcribes the structural genes.
Tryptophan is bound to the repressor.
Chapter 16 Solutions
EBK CONCEPTS OF GENETICS
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
- Consider the lac operon of E. coli. Specifically, explain the following: a. Describe the overall chromosomal structure/organization of the operon, indicating the location and function of the regulatory regions and the structural genes. b. Is lac a catabolic or anabolic pathway? Explain. Is the operon inducible or repressible? Explain. c. Describe the mechanisms involved in negative control & positive controlarrow_forwardIn the topic about prokaryotic gene expression regulation, we learned about the LacI-, LacIS, and LacOc mutations. Based on your knowledge of allosteric regulation, invent and describe a hypothetical mutation that would produce constitutive expression of the Lac operon but is not a mutation that occurs in the Lac operator (that is, it must be a different mutation than a LacOc type mutation) and is not a mutation to the DNA binding domain of LacI (that is, it must also be a different mutation than a LacI- type mutation). Clearly mention where in the prokaryotic genome this mutation would occur, and explain the logic behind how that mutation would produce constitutive Lac operon expression.arrow_forwardINTERPRET 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_forward
- Attenuation of the trp operon was viewed as a relatively inefficient way to achieve genetic regulation when it was first discovered in the 1970s. Since then, however, attenuation has been found to be a relatively common regulatory strategy. Assuming that attenuation is a relatively inefficient way to achieve genetic regulation, what might explain its widespread occurrence?arrow_forward. a. How many ribosomes are required (at a minimum)for the translation of trpE and trpC from a singletranscript of the trp operon?b. How would you expect deletion of the two tryptophan codons in the RNA leader to affect theexpression of the trpE and trpC genes?arrow_forwardThe dlagram below represents the tryptophan operon with the trp leader MRNA transcript enlarged to represent the AUG transiation start codon, two consecutive tryptophan amino acld codons (UGGUGG), and 4 regions (1, 2, 3, and 4) that base pair to form different hairpin-loop structures in the MRNA leader region. What would happen in this MRNA leader region when cells encounter very low levels of tryptophan in Its environment? Leader region trpE trpD trpC trpB trpA DNA 5' 3' Transcription trp leader sequence mRNA UGGUGG (tryptophan codons) AUG UUUUUU 1 3 4. The translating ribosome would stall at the two tryptophan codons, causing the formation of a hairpin-loop botween regions 3 and 4 to promote transcription of the trp operon. The translating ribosome would stall at the two tryptophan codons causing formation of hairpin-loop between regions 2 and 3, which functions as an anti-lerminator of transcription The translating ribosome would stall at the two tryptophan codons causing formation…arrow_forward
- For the following questions, describe the expression levels of the structural genes in the Lac operon under the conditions described. In the absence of lactose, the structural genes will:[ Select ] ["No longer be expressed", "Be constantly expressed", "Be deleted from the operon"] In the presence of lactose, the structural genes will:[ Select ] ["No longer be expressed", "Be constantly expressed", "Be deleted from the operon"] In the absence of lactose and the promoter sequence was mutated such that the RNA polymerase can no longer bind, the structural genes will:[ Select ] ["No longer be expressed", "Be constantly expressed", "Be deleted from the operon"] In the presence of lactose and the promoter sequence was mutated such that the RNA polymerase can no longer bind, the structural genes will:[ Select ] ["No longer be expressed", "Be constantly expressed", "Be deleted from the operon"] In the absence of lactose and the lacI repressor gene is mutated such that the repressor protein…arrow_forwardThe streptolysin S toxin made by S. pyogenes is encoded by a 9-gene operon, sagABCDEFGHI. Thinking about what a 3-line diagram would look like for this operon, answer the following questions. Write numeric answers only. For example, if your answer is 6 promoters, write only 6. 1) How many promoters control the expression of these genes? 2) How many locations does RNA Polymerase bind to get full expression of these genes? 3) How many ribosome binding sites are needed for full protein expression? 4) How many start codons will be needed for full protein expression? 5) How many mRNA strands will be produced with full operon expression? 6) How many proteins will be produced with full protein expression? 1arrow_forwardThe diagram below represents the tryptophan operon with the trp leader mRNA transcript enlarged to represent the AUG translation start codon, two consecutive tryptophan amino acid codons (UGGUGG), and 4 regions (1, 2, 3, and 4) that base pair to form different hairpin-loop structures in the mRNA leader region. Suppose a mutant bacteria has region 3 of the trp operon attenuator region mutated so that it cannot base pair normally. Would the bacteria grow in the absence of the amino acid tryptophan? (hint: in order for bacteria to grow in absence of tryptophan it should be able to synthesize its own tryptophan) Leader region trpE trpD trpC trpB trpA DNA 5' 3' Transcription trp leader sequence MRNA AUG UGGUGG UUUUUU 1 2 3 (tryptophan codons) There is insufficient information to answer the question. Yes No O Oarrow_forward
- The diagram below represents the tryptophan operon with the trp leader mRNA transcript enlarged to represent the AUG translation start codon, two consecutive tryptophan amino acid codons (UGGUGG), and 4 regions (1, 2, 3, and 4) that base pair to form different hairpin-loop structures in the MRNA leader region. Suppose a mutant bacteria has region 4 of the trp operon attenuator region mutated so that it cannot base pair normally. Would the bacteria grow in the absence of the amino acid tryptophan? (hint: in order for bacteria to grow in absence of tryptophan it should be able to synthesize its own tryptophan) Lead&r region trpE trpD trpC trpB trpA DNA 5' 3' Transcription trp leader sequence MRNA UGGUGG 1 (tryptophan codons) AUG UUUUUU No There is insutficient information to answer the question. O Yesarrow_forwardThe trp operon, found in E. coli, is a group of genes that encode biosynthetic enzymes for the amino acid tryptophan. (i) Draw a schematic diagram showing the components involved in regulation of the tryptophan operon. (ii) How does the regulation of the trp operon differ from the regulation of the lac operon? Explain.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_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning
Biology (MindTap Course List)
Biology
ISBN:9781337392938
Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. Berg
Publisher:Cengage Learning
Bacterial Genomics and Metagenomics; Author: Quadram Institute;https://www.youtube.com/watch?v=_6IdVTAFXoU;License: Standard youtube license