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... Catabolite Repression of the lac Operon Lactose is not the preferred carbohydrate source for E. coli. If lactose and glucose are present, the cell will use all of the glucose before the lac operon is turned on. This type of control is termed catabolite repression. To prevent lactose metabolism, a se ...
... Catabolite Repression of the lac Operon Lactose is not the preferred carbohydrate source for E. coli. If lactose and glucose are present, the cell will use all of the glucose before the lac operon is turned on. This type of control is termed catabolite repression. To prevent lactose metabolism, a se ...
SBI 4U Genetics 5
... cell’s DNA and causes substitution or frameshift changes. EG. Gasoline fumes, nitrites and compounds found in cigarette smoke Physical mutagens: physically change the DNA ...
... cell’s DNA and causes substitution or frameshift changes. EG. Gasoline fumes, nitrites and compounds found in cigarette smoke Physical mutagens: physically change the DNA ...
11.4.14 KEY - Iowa State University
... 7. Describe the three different types of mutations that are possible in structural genes. 1. gene product is present and inactive due to mutation, such as change of one base for another that results in a different codon for a different amino acid for another 2. the protein is not present (called a n ...
... 7. Describe the three different types of mutations that are possible in structural genes. 1. gene product is present and inactive due to mutation, such as change of one base for another that results in a different codon for a different amino acid for another 2. the protein is not present (called a n ...
Coarse-Graining of Macromolecules
... cycle and bacterial growth in presence of different sugars led to picture of gene regulation. Use of sugars other than glucose (such as lactose) seemed to be tightly controlled. ...
... cycle and bacterial growth in presence of different sugars led to picture of gene regulation. Use of sugars other than glucose (such as lactose) seemed to be tightly controlled. ...
Translation
... •Cells are able to "turn on" or "turn off" genes when their products are not required in cell metabolism or control. • Regulation of gene expression is now only being to be fully understood and is a major area of research today. ...
... •Cells are able to "turn on" or "turn off" genes when their products are not required in cell metabolism or control. • Regulation of gene expression is now only being to be fully understood and is a major area of research today. ...
APh 162 – Cellular Decision Making Measuring Gene Expression
... eaten by the cells, we use the inducer IPTG. This small molecule interacts with Lac repressor in much the same way that the real sugar does except that it cannot be cleaved by the enzyme beta-galactosidase, making it a useful experimental substrate. In the absence of lactose or IPTG, Lac repressor b ...
... eaten by the cells, we use the inducer IPTG. This small molecule interacts with Lac repressor in much the same way that the real sugar does except that it cannot be cleaved by the enzyme beta-galactosidase, making it a useful experimental substrate. In the absence of lactose or IPTG, Lac repressor b ...
homework
... D. the sequential development of an animal’s basic body plan The lac operon is found in _______________________ A. prokaryotes B. eukaryotes The TATA box sequence is found in _____________________ cells A. prokaryotes B. eukaryotes The function of the TATA box is to ________________________________. ...
... D. the sequential development of an animal’s basic body plan The lac operon is found in _______________________ A. prokaryotes B. eukaryotes The TATA box sequence is found in _____________________ cells A. prokaryotes B. eukaryotes The function of the TATA box is to ________________________________. ...
Regulation of gene expression
... Genetic regulation • Genotype is not phenotype: bacteria possess many genes that they are not using at any particular time. • Transcription and translation are expensive; why spend ATP to make an enzyme you don’t need? • Operon – Genes physically adjacent regulated together ...
... Genetic regulation • Genotype is not phenotype: bacteria possess many genes that they are not using at any particular time. • Transcription and translation are expensive; why spend ATP to make an enzyme you don’t need? • Operon – Genes physically adjacent regulated together ...
Gene Expression and Regulation
... through a process called differentiation • Differentiation is controlled by hox genes. – Some genes get turned off permanently (your liver cells do not express genes that make proteins in the skin) – Like master controls of what cells become what part of the body – Manipulation of these genes can al ...
... through a process called differentiation • Differentiation is controlled by hox genes. – Some genes get turned off permanently (your liver cells do not express genes that make proteins in the skin) – Like master controls of what cells become what part of the body – Manipulation of these genes can al ...
Powerpoint file - revised
... Most prokaryotic genes are regulated in units called operons (Jacob and Monod, 1960) Operon: a coordinated unit of gene expression consisting of one or more related genes and the operator and promoter sequences that regulate their transcription. The mRNAs thus produced are “polycistronic’—multiple g ...
... Most prokaryotic genes are regulated in units called operons (Jacob and Monod, 1960) Operon: a coordinated unit of gene expression consisting of one or more related genes and the operator and promoter sequences that regulate their transcription. The mRNAs thus produced are “polycistronic’—multiple g ...
PowerPoint Presentation - No Slide Title
... The trp operon is a biosynthetic operon - it codes for the enzymes that make the amino acid tryptophan. This pathway should be kept in the “off” state when tryptophan is present. When tryptophan is absent, the bacteria need to make it from scratch. Now the pathway needs to be turned on. ...
... The trp operon is a biosynthetic operon - it codes for the enzymes that make the amino acid tryptophan. This pathway should be kept in the “off” state when tryptophan is present. When tryptophan is absent, the bacteria need to make it from scratch. Now the pathway needs to be turned on. ...
Operon Comparison Chart
... INDUCIBLE - Operon is usually OFF (can be turned on) - Repressor is made in the ACTIVE form - Ex. LAC OPERON - Breaks down lactose to get ATP - Only switched ON when lactose (allolactose) is present (it only needs to be on if lactose is available to be broken down!!) - Allolactose is an inducer - Du ...
... INDUCIBLE - Operon is usually OFF (can be turned on) - Repressor is made in the ACTIVE form - Ex. LAC OPERON - Breaks down lactose to get ATP - Only switched ON when lactose (allolactose) is present (it only needs to be on if lactose is available to be broken down!!) - Allolactose is an inducer - Du ...
foga i - is there such a thing as a gene? = formatting the
... Operations involving glucose transport components and adenylate cyclase IIAGlc-P + glucose(ext) ==> IIAGlc + glucose-6-P(int) IIAGlc-P + adenylate cyclase(inactive) ==> adenylate cylase(active) Adenylate cyclase(active) + ATP ==> cAMP + P~P Operations involving transcription factors Crp + cAMP ==> C ...
... Operations involving glucose transport components and adenylate cyclase IIAGlc-P + glucose(ext) ==> IIAGlc + glucose-6-P(int) IIAGlc-P + adenylate cyclase(inactive) ==> adenylate cylase(active) Adenylate cyclase(active) + ATP ==> cAMP + P~P Operations involving transcription factors Crp + cAMP ==> C ...
1. The I gene determines the synthesis of a repressor molecule
... You are told that a, b, and c represent lacI, lacO, and lacZ, but you do not know which is which. Both a– and c– have constitutive phenotypes (lines 1 and 2) and therefore must represent mutations in either the operator (lacO) or the repressor (lac I). b– (line 3) shows no ß-gal activity and by elim ...
... You are told that a, b, and c represent lacI, lacO, and lacZ, but you do not know which is which. Both a– and c– have constitutive phenotypes (lines 1 and 2) and therefore must represent mutations in either the operator (lacO) or the repressor (lac I). b– (line 3) shows no ß-gal activity and by elim ...
Describe the operon hypothesis and discuss
... __ CAP model: catabolite induction: with decrease in glucose -> increase in cAMP cAMP-CAP binds to promoter site therefore, transcription -> lactose metabolism = 3 points (above require explanation & example) __ Adaptive significance = 2 points __ Final fate of mRNA transcribed = 2 points Max. = 5 ...
... __ CAP model: catabolite induction: with decrease in glucose -> increase in cAMP cAMP-CAP binds to promoter site therefore, transcription -> lactose metabolism = 3 points (above require explanation & example) __ Adaptive significance = 2 points __ Final fate of mRNA transcribed = 2 points Max. = 5 ...
Regulation of Gene Expression
... – Remember that a promoter is where RNA polymerase binds to DNA to begin transcription – Occurs in prokaryotic genomes ...
... – Remember that a promoter is where RNA polymerase binds to DNA to begin transcription – Occurs in prokaryotic genomes ...
Jacob and Monod were the first scientists to elucidate a
... The function of this enzyme is not known. It is coded for by the gene LacA. These three enzymes appear adjacent to each other on the E. Coli genome. They are preceded by a region which is responsible for the regulation of the lactose metabolic genes. Note that there is more to regulation than the ob ...
... The function of this enzyme is not known. It is coded for by the gene LacA. These three enzymes appear adjacent to each other on the E. Coli genome. They are preceded by a region which is responsible for the regulation of the lactose metabolic genes. Note that there is more to regulation than the ob ...
Other Plasmid Maps Feature list descriptions
... LacO is a regulatory gene of the lac operon. If lactose is missing from the growth medium, the repressor binds very tightly to a short DNA sequence just downstream of the promoter near the beginning of lacZ called the lac operator. The repressor binding to the operator interferes with binding of RNA ...
... LacO is a regulatory gene of the lac operon. If lactose is missing from the growth medium, the repressor binds very tightly to a short DNA sequence just downstream of the promoter near the beginning of lacZ called the lac operator. The repressor binding to the operator interferes with binding of RNA ...
Problems 11
... (5pts) An allosteric repressor protein binds DNA in the presence of ethanol and does not in its absence…. The binding of ethanol to repressor alters the protein’s shape to its active form. (5pts) Mutations in two loci (c and d) affect the control of this operon. Strain 2 indicates d- is recessive, s ...
... (5pts) An allosteric repressor protein binds DNA in the presence of ethanol and does not in its absence…. The binding of ethanol to repressor alters the protein’s shape to its active form. (5pts) Mutations in two loci (c and d) affect the control of this operon. Strain 2 indicates d- is recessive, s ...
Nessun titolo diapositiva
... - It is constitutively expressed (10 molecules per cell) - LacI repressor is a tetrameric protein -The repressor protein has the greatest affinity for binding to O1 and lesser affinity to O2 and O3 ...
... - It is constitutively expressed (10 molecules per cell) - LacI repressor is a tetrameric protein -The repressor protein has the greatest affinity for binding to O1 and lesser affinity to O2 and O3 ...
Controlling Gene Expression
... •B-galactosidase: enzyme responsible for the degradation of lactose The lac operon is a cluster of three genes that code for the metabolism of lactose: lacZ codes for B-galactosidase lacY codes for B-galactosidase permease which lets lactose cross the cell membrane lacA codes for transacetylase; unk ...
... •B-galactosidase: enzyme responsible for the degradation of lactose The lac operon is a cluster of three genes that code for the metabolism of lactose: lacZ codes for B-galactosidase lacY codes for B-galactosidase permease which lets lactose cross the cell membrane lacA codes for transacetylase; unk ...
Lecture Guide_Regulation of Gene Expression(Ch 7.5-7.6)
... Regulation of Gene Expression (Chapter 7) Reading Guide 1. Why is it important for bacterial cells to be able to regulate gene expression? Provide an example. ...
... Regulation of Gene Expression (Chapter 7) Reading Guide 1. Why is it important for bacterial cells to be able to regulate gene expression? Provide an example. ...
Lac operon
lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is not available. Gene regulation of the lac operon was the first genetic regulatory mechanism to be understood clearly, so it has become a foremost example of prokaryotic gene regulation. It is often discussed in introductory molecular and cellular biology classes at universities for this reason.Bacterial operons are polycistronic transcripts that are able to produce multiple proteins from one mRNA transcript. In this case, when lactose is required as a sugar source for the bacterium, the three genes of the lac operon can be expressed and their subsequent proteins translated: lacZ, lacY, and lacA. The gene product of lacZ is β-galactosidase which cleaves lactose, a disaccharide, into glucose and galactose. LacY encodes lactose permease, a protein which becomes embedded in the cytoplasmic membrane to enable transport of lactose into the cell. Finally, lacA encodes galactoside O-acetyltransferase. Layout of the lac operon.It would be wasteful to produce the enzymes when there is no lactose available or if there is a more preferable energy source available, such as glucose. The lac operon uses a two-part control mechanism to ensure that the cell expends energy producing the enzymes encoded by the lac operon only when necessary. In the absence of lactose, the lac repressor halts production of the enzymes encoded by the lac operon. In the presence of glucose, the catabolite activator protein (CAP), required for production of the enzymes, remains inactive, and EIIAGlc shuts down lactose permease to prevent transport of lactose into the cell. This dual control mechanism causes the sequential utilization of glucose and lactose in two distinct growth phases, known as diauxie.