Biochemistry
9th Edition
ISBN: 9781319114671
Author: Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.
Publisher: W. H. Freeman
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Question
Chapter 32, Problem 4P
Interpretation Introduction
Interpretation:
The two important ways in which the lac repressor and pur repressor differences can be determined.
Concept introduction:
E. Coli contains of lac operon, which is involved in lactose
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- True or False. Explain. A) At no time during protein synthesis does an amino acid make direct contact with the mRNA being translated. B) Because the two strands of DNA are complementary, the mRNA of a gene can be synthesized using either strand as a template.arrow_forwardAAAGAGAAAAGAAUA to AAAGAGAAAUGAAUA. Suppose the codon sequence has a single base pair mutation If the old protein sequence was Lys-Glu-Lys-Arg-Ile, what will be the new sequence encoded by the mutant gene? (Use the 3-letter amino acid abbreviations with hyphens and no spaces in between, i.e. Ser-Asn-Tyr-Leu-Pro.) Submit Answer Retry Entire Group No more group attempts remainarrow_forwardprotein. You create a mouse line with Cas9 under control of a brain-specific enhancer, while the short guide RNA complementary to the first exon of Gene Y is expressed in all tissues. You subsequently sequence Gene Y in both brain and liver tissue. What would expect in each tissue? You can assume that the CRISPRICas9 system will impact both copies of Gene Y in cells, and that the first exon of Gene Y is necessary for Gene Ys function. a. Liver: Functional Gene Y; Brain: Functional Gene Y b. Liver: Nonfunctional Gene Y; Brain: Funtional Gene Y c. Liver: Functional Gene Y; Brain: Nonfunctional Gene Y d. Liver: Nonfunctional Gene Y; Brain: Nonfunctional Gene Yarrow_forward
- Transcriptional regulation You are interested in studying the transcriptional regulation of Glp1 promoter. This gene contains a binding site for two proteins A and B. Proteins A and B cannot bind to the DNA at the same time due to steric interference caused by a slight overlap in their binding sites. The binding sites of protein A and protein B can be seen in the figure below. Protein A binds to Site C and Protein B binds to site D. To assess whether either A or B have an influence on Glp1 expression, you create mutations in the DNA that selectively remove the non-overlapping sequences of binding site C or binding site D. You then examine Glp1 mRNA production within adult liver cells. You receive the following data. Experiment number Binding site C Binding site D Glp1 mRNA levels 1 + + high 2 + - high 3 - + none 4 - - none += binding site present, -= binding site absent What does this data tell us about which protein is…arrow_forward. CTP 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 a mutator phenotype. Explain the basis for these observations.arrow_forwardRegulation of Genes and Their products 1. Given the following genotypes, explain how the mutation (identified by a (-) superscript) wil affect E. coll grown in lactose medium. Will the lac operon be on or off? Will there be a complete set of gene products from the lac operon? What will be the implication of the missing gene product, if ever? Will the cell be able to survive in the lactose medium or not? a. I+p+o+z- y+ b. i- p+o+z+y+ c. i+p+o- z+y+ d. i+p- o+z+y+ 2. In terms of the trp operon, differentiate between two normal bacterial cultures, one grown in a medium supplied with tryptophan and the other medium without tryptophan. 3. Experiments show that mutations at gene E lead to non-repressible transcription of trp genes. Why?arrow_forward
- Plz answer ASAP. I will thumb up You are studying the regulation of the lactose operon in Escherichia coli, by measuring expression of the lacZ gene (i.e production of beta-galactosidase).(a) You identify several loss-of-function mutations in which lacZ is never expressed, in the presence and absence of glucose and lactose. What components of the lac operon could be mutated to produce this phenotype? List all possibilities.arrow_forwardI am more confused. how about we start from begining, you post answers on here, and then we go from there? 1. Identify the open reading frame in the following DNA sequence, the protein that this gene encodes for, its function, and the source. 2. "Look carefully at the DNA sequence and identify the start site for transcription" 3. Click on the DNA sequence from the start site of transcription, select all of the sequence, and copy the sequence. Go to the National Center for Biotechnology Information (NCBI) website http://www.ncbi.nlm.nih.gov/. Click on BLAST on the right-hand side under “Popular Resources.” BLAST is a program that will allow you to find the protein sequence for the DNA sequence (gene) you submit. Next click on blastx (translated nucleotide protein). Paste the DNA sequence into the box under “Entry Query Sequence.” Scroll down and click BLAST. The search may take a few seconds; the page will keep updating until the search is completed. You do not need to enter any…arrow_forwardMatch the term with its description. cAMP Allows lactose to enter the cell and product of the lacY gene A regulatory sequence between the promoter and the structural genes of the lac operon When glucose levels are high, intracellular levels of this molecule are low Binds to and inhibits the function of the lac repressor when lactose is presentarrow_forward
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