lac mutation (gene regulation)
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This document discusses gene regulation through operons such as the lac, ara, and trp operons. It describes operons as units of coordinate gene expression that include structural genes and regulatory elements. Operons are regulated by repressor proteins that bind to the operator region and control transcription. There are two types of negative gene regulation: repressible operons where a repressor protein binds the operator to shut off transcription, and inducible operons where binding of an inducer inactivates the repressor and turns on transcription. Common mutations in regulated operons include constitutive mutations where genes are always transcribed and uninducible mutations where expression cannot be induced. IPTG is described as a gratuitous inducer that mim
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Lac operon by khirood
The document discusses the lac operon in E. coli. The lac operon is a set of genes that allows the bacteria to use lactose as an energy source. It includes genes that encode lactose transport proteins and beta-galactosidase, which breaks down lactose. The lac operon is regulated by the lac repressor and cAMP such that transcription only occurs when glucose is low and lactose is present.
Lac operon
This document summarizes the lac operon in E. coli, which regulates genes involved in lactose metabolism. The lac operon contains structural genes that encode beta-galactosidase, galactoside permease, and thiogalactoside transacetylase. These genes are regulated by a repressor protein that binds to the operator region and prevents transcription under non-inducing conditions when lactose is absent. However, in the presence of lactose, allolactose is produced and binds to the repressor, causing a conformational change that prevents it from binding to the operator. This allows RNA polymerase to bind to the promoter and initiate transcription of the structural genes, allowing lactose to be metabol
Deepali lac operon
The sldes shares about the negative and positive regulation of lac operon under different concentration of glucose/lactose.
08 lac operon
The lac operon controls genes involved in lactose metabolism in E. coli bacteria. It consists of three genes that are transcribed together. When glucose is present, a repressor protein binds to the operator site of the lac operon and blocks transcription. When lactose is present, an allosteric change in the repressor protein causes it to detach from the operator site, allowing RNA polymerase to bind and transcribe the genes. However, in the presence of both glucose and lactose, transcription does not occur as RNA polymerase is unstable and falls off the promoter site readily. Only when glucose is absent and lactose is present, an activator protein binds and stabilizes RNA polymerase, leading to efficient transcription of the lac oper
Lac operon
The document discusses gene regulation and the lactose operon. It defines positive and negative control of gene expression, where activator and repressor proteins respectively allow or hinder transcription. The lactose operon was the first discovered operon in E. coli and contains three genes for lactose metabolism. It is regulated by the lactose repressor protein which provides negative control and the catabolite activator protein which enables positive control and transcription in the presence of lactose.
Lac operon
The lac operon controls genes involved in lactose metabolism in E. coli. It consists of three structural genes - lacZ, lacY, and lacA - that are regulated by a single promoter. Expression of the lac genes is controlled by the lac repressor protein, which binds to the operator region and blocks transcription unless lactose is present. When lactose is detected, it causes an allosteric change in the repressor, releasing it from the operator and allowing transcription. Glucose also prevents expression through catabolite repression by inhibiting the activator protein required for stable transcription initiation.
Lactose Operon
The lactose operon controls the metabolism of lactose in E. coli. It consists of three structural genes - lacZ, lacY, and lacA - that encode enzymes for breaking down lactose. These genes are regulated by one regulatory gene, lacI, which produces the lac repressor protein.
When lactose is absent or glucose is present, the lac repressor binds to the operator region and blocks transcription of the structural genes. But when lactose is available and glucose levels are low, lactose binds to the lac repressor and inactivates it, allowing RNA polymerase to bind the promoter and transcribe the structural genes to produce the enzymes for lactose breakdown. This allows the bacteria to metabolize
Lactose operon/metabolism of lactose in E.Coli
The document summarizes the lac operon in E. coli, which regulates the metabolism of lactose. The lac operon consists of structural genes (lacZYA) that encode enzymes for lactose catabolism, and control genes (promoter, operator, and repressor) that regulate expression. In the absence of lactose, the repressor binds the operator/promoter region, blocking transcription. In the presence of lactose or inducer molecules like IPTG, the repressor binds lactose instead, allowing transcription and expression of the structural genes. Glucose inhibits induction by lowering cellular cAMP levels needed for RNA polymerase binding to the promoter. The lac operon demonstrates negative and positive regulation of gene expression.
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Lac operon by khirood
The document discusses the lac operon in E. coli. The lac operon is a set of genes that allows the bacteria to use lactose as an energy source. It includes genes that encode lactose transport proteins and beta-galactosidase, which breaks down lactose. The lac operon is regulated by the lac repressor and cAMP such that transcription only occurs when glucose is low and lactose is present.
Lac operon
This document summarizes the lac operon in E. coli, which regulates genes involved in lactose metabolism. The lac operon contains structural genes that encode beta-galactosidase, galactoside permease, and thiogalactoside transacetylase. These genes are regulated by a repressor protein that binds to the operator region and prevents transcription under non-inducing conditions when lactose is absent. However, in the presence of lactose, allolactose is produced and binds to the repressor, causing a conformational change that prevents it from binding to the operator. This allows RNA polymerase to bind to the promoter and initiate transcription of the structural genes, allowing lactose to be metabol
Deepali lac operon
The sldes shares about the negative and positive regulation of lac operon under different concentration of glucose/lactose.
08 lac operon
The lac operon controls genes involved in lactose metabolism in E. coli bacteria. It consists of three genes that are transcribed together. When glucose is present, a repressor protein binds to the operator site of the lac operon and blocks transcription. When lactose is present, an allosteric change in the repressor protein causes it to detach from the operator site, allowing RNA polymerase to bind and transcribe the genes. However, in the presence of both glucose and lactose, transcription does not occur as RNA polymerase is unstable and falls off the promoter site readily. Only when glucose is absent and lactose is present, an activator protein binds and stabilizes RNA polymerase, leading to efficient transcription of the lac oper
Lac operon
The document discusses gene regulation and the lactose operon. It defines positive and negative control of gene expression, where activator and repressor proteins respectively allow or hinder transcription. The lactose operon was the first discovered operon in E. coli and contains three genes for lactose metabolism. It is regulated by the lactose repressor protein which provides negative control and the catabolite activator protein which enables positive control and transcription in the presence of lactose.
Lac operon
The lac operon controls genes involved in lactose metabolism in E. coli. It consists of three structural genes - lacZ, lacY, and lacA - that are regulated by a single promoter. Expression of the lac genes is controlled by the lac repressor protein, which binds to the operator region and blocks transcription unless lactose is present. When lactose is detected, it causes an allosteric change in the repressor, releasing it from the operator and allowing transcription. Glucose also prevents expression through catabolite repression by inhibiting the activator protein required for stable transcription initiation.
Lactose Operon
The lactose operon controls the metabolism of lactose in E. coli. It consists of three structural genes - lacZ, lacY, and lacA - that encode enzymes for breaking down lactose. These genes are regulated by one regulatory gene, lacI, which produces the lac repressor protein.
When lactose is absent or glucose is present, the lac repressor binds to the operator region and blocks transcription of the structural genes. But when lactose is available and glucose levels are low, lactose binds to the lac repressor and inactivates it, allowing RNA polymerase to bind the promoter and transcribe the structural genes to produce the enzymes for lactose breakdown. This allows the bacteria to metabolize
Lactose operon/metabolism of lactose in E.Coli
The document summarizes the lac operon in E. coli, which regulates the metabolism of lactose. The lac operon consists of structural genes (lacZYA) that encode enzymes for lactose catabolism, and control genes (promoter, operator, and repressor) that regulate expression. In the absence of lactose, the repressor binds the operator/promoter region, blocking transcription. In the presence of lactose or inducer molecules like IPTG, the repressor binds lactose instead, allowing transcription and expression of the structural genes. Glucose inhibits induction by lowering cellular cAMP levels needed for RNA polymerase binding to the promoter. The lac operon demonstrates negative and positive regulation of gene expression.
Lac operon
Each cell in the human contains all the genetic material for the growth and development of a human
Some of these genes will be need to be expressed all the time
These are the genes that are involved in of vital biochemical processes such as respiration
Other genes are not expressed all the time
They are switched on an off at need
Regulation of lac operon positive nd negative
The document summarizes the regulation of the lac operon in E. coli. It describes how the lac operon can be regulated both positively and negatively in response to the presence of lactose or glucose. In negative regulation, the lac repressor binds to the operator site in the absence of lactose, preventing transcription. In the presence of lactose, it binds to allolactose and dissociates from DNA, allowing transcription. Positive regulation involves cAMP and the catabolite activator protein activating transcription in the absence of glucose.
Lac operon
This is my first presentation share in this platform. Hope this is helpful for you! Here, I have tried to explain MECHANISM OF LAC OPERON in E.Coli in informative and crisp manner with simple language and few images.
Lac operon
Bacteria regulate gene expression through operons, which are groups of functionally related genes that are controlled together. Operons can be regulated positively or negatively in response to environmental conditions. The lac operon in E. coli controls the transport and metabolism of lactose and consists of structural genes regulated by a promoter, terminator, and repressor. The lac operon is negatively regulated - the lac repressor normally binds the operator to prevent transcription, but is released when bound by the inducer allolactose, allowing expression. Transcription is also controlled by the availability of glucose and regulated by the catabolite activator protein CAP.
Lac operon concept
Includes definition, discovery.Enzyme induction is a process in which a molecule (e.g., a drug) induces (i.e., initiates or enhances) the expression of an enzyme.
The induction of heat shock proteins in the fruit fly Drosophila melanogaster.
The Lac operon is an interesting example of how gene expression can be regulated.
Viruses, despite having only a few genes, possess mechanisms to regulate their gene expression, typically into an early and late phase, using collinear systems regulated by anti-terminators (lambda phage) or splicing modulators (HIV).
Gal4 is a transcriptional activator that controls the expression of GAL1, GAL7, and GAL10 (all of which code for the metabolic of galactose in yeast). The GAL4/UAS system has been used in a variety of organisms across various phyla to study gene expression.
Lac operon
The document summarizes the lac operon which regulates lactose metabolism in E. coli bacteria. The lac operon consists of structural genes that encode enzymes for lactose breakdown. It is regulated by the lac repressor protein which binds to the operator region in the absence of lactose to prevent transcription. In the presence of lactose, the repressor detaches from the operator allowing transcription. A second control involves the catabolite activator protein (CAP) and cyclic AMP (cAMP) which activate transcription in the absence of glucose. The mechanism of induction and classification of regulatory mutants are also described.
Lac operon
The operon theory proposes that genes are organized into operons - clusters of genes under the control of a single promoter. An operon contains a promoter, operator, and multiple structural genes. The lac operon in E. coli regulates genes involved in lactose metabolism. It is negatively regulated - in the absence of lactose, a repressor binds the operator to prevent transcription, but lactose or allolactose induce transcription by binding to the repressor. The operon theory explains how bacteria regulate gene expression in response to environmental conditions.
Lac operon system
This presentation will give an introduction to operon and to its history. And gives a detailed or brief explanation about lac operon, its gene composition , their functions, its working mechanism and the use of lac operon in molecular biology.
Lac Operon for class 12th
The document discusses gene regulation and the lac operon. It describes the lac operon as having structural genes, an operator, and a promoter that are required for gene expression. The lac operon was first defined in studies of lactose metabolism in E. coli. It introduced the terms "operon" and "operator" and showed that a regulatory gene encodes a repressor that binds to the operator to control transcription of the structural genes in response to the presence or absence of an inducer molecule like lactose.
Lac operon (1)
The regulation of gene expression is critical for all organisms. There are two main types of genes - constitutive genes that are always "on" and non-constitutive or luxury genes that are regulated. Gene regulation involves turning genes on and off through transcriptional and translational control. Key elements that regulate genes include regulatory genes, structural genes, and regulatory elements in DNA that control transcription. Regulation can occur at the level of DNA, transcription, mRNA processing, translation, and post-translation. The lac operon in E. coli is an example of negative inducible gene regulation involving a repressor, operator, and inducer to control lactose metabolism genes.
Lac Operon
The document summarizes the lac operon in E. coli, which allows the bacteria to transport and metabolize lactose. The lac operon is made up of three coding regions that are regulated by a promoter, operator, and terminator. It is environmentally regulated, meaning the presence of lactose affects whether or not the genes are expressed. Specifically, lactose binds to the LacI repressor, preventing it from blocking RNA polymerase and allowing expression of the lac genes and digestion of lactose.
Gene regulation in prokaryotes
A gene is basic unit of heredity and a sequence of nucleotides in DNA that Encodes synthesis of Gene product either RNA
operon concept
The document discusses operons, which are groups of prokaryotic genes that are transcribed together to serve a single purpose. Jacob and Monod discovered the operon concept in 1961 while studying E. coli metabolism. An operon contains an operator, promoter, and genes. Regulatory proteins can control operon transcription by repressing or inducing it. Examples discussed include the lac and trp operons, which use different mechanisms of negative and positive induction/repression to control gene expression based on environmental conditions.
6ed68c 20110926 chapter26-outline
The operon is a unit of bacterial gene expression that includes structural genes and control elements in DNA. The lac operon is an example of negative inducible regulation, where a repressor protein binds to the operator to prevent transcription unless the inducer is present. The lac repressor is a tetramer controlled by allosteric changes - binding of the inducer inactivates the repressor. Other operons like trp use different mechanisms of regulation including attenuation, where transcription is controlled by RNA secondary structure formation. Translation can also be regulated through features in the 5' UTR of mRNAs.
Ara operon
The document summarizes the ara operon, which regulates genes involved in the metabolism of arabinose sugar. It consists of 3 key components: structural genes that encode enzymes for arabinose catabolism, an operator site that binds a repressor protein, and a promoter that enables transcription. Specifically, the ara operon contains 3 structural genes - araB, araA, araD - that code for enzymes converting arabinose into an intermediate. It is regulated by the araC gene product, which can act as both a repressor and activator depending on arabinose and glucose levels. When arabinose is low and glucose high, the araC repressor binds the operator sites, forming a DNA loop that
Lac operon
The lac operon contains three genes - lacZ, lacY, and lacA - that are transcribed together and encode proteins involved in lactose metabolism. The operon contains regulatory sequences including a promoter where RNA polymerase binds, an operator where the lac repressor binds to block transcription, and a CAP binding site where the catabolite activator protein binds to promote transcription when glucose levels are low. The lac operon is expressed only when lactose is present and glucose is absent, regulated by the lac repressor and CAP in response to lactose and glucose levels.
Lac operon
The lac operon controls the breakdown of lactose in E. coli bacteria. It consists of three structural genes (lacZ, lacY, lacA) that are regulated by a single promoter and operator region. In the absence of lactose, a lac repressor binds to the operator, preventing transcription of the structural genes. When lactose is present, it binds to the repressor and causes a conformational change, releasing it from the operator and allowing transcription. Mutations in the operator, structural genes, or promoter region provided insights into the operon's control mechanism.
Regulation of gene expression
This document discusses the regulation of gene expression. It defines key terms like gene, genome, and gene expression. It explains that some genes are expressed continuously while others are only expressed under certain conditions. There are mechanisms that allow cells to express or turn off certain genes as needed. Regulation of gene expression is essential for optimal energy use and the growth, development, and existence of organisms. There are two main types of regulation: positive regulation which increases gene expression, and negative regulation which decreases it. The document then focuses on prokaryotic gene expression, explaining operons as groups of genes expressed together from a single promoter. It provides the example of the lac operon in E. coli, which expresses genes for lactose metabolism
Lac Operon
The document summarizes gene regulation in prokaryotes and eukaryotes. In prokaryotes, genes are organized into operons that are regulated by repressor or inducible systems like the tryptophan and lactose operons. The tryptophan operon is turned off by a repressor when tryptophan levels are high. The lactose operon is induced when lactose is present and glucose levels are low. In eukaryotes, gene expression is controlled through chromatin structure, pre-transcriptional and post-transcriptional regulation involving transcription factors and RNA processing, and pre-translational and post-translational regulation involving translation initiation, protein processing and degradation.
Operon
This document provides an overview of gene regulation in prokaryotes using the lac operon in E. coli as an example. It explains that genes are regulated to control which proteins are expressed at different times. The lac operon consists of structural genes that encode enzymes for lactose metabolism, as well as a regulatory gene that produces a repressor protein. In the absence of the lactose inducer, the repressor binds to the operator region and prevents transcription. When lactose is present, it binds to the repressor and causes a conformational change that prevents it from binding to the operator, allowing transcription.
differernt types of Operon concepts
total description of lactose operon, galactose operon, arabinose operon, tryptophan operon and their regulations and mechanisms
LAC OPERON.pptx
The document discusses gene regulation in prokaryotes using the lac operon in E. coli as an example. The lac operon consists of structural genes that encode proteins for lactose metabolism and regulatory genes that control their expression. In the absence of lactose, a repressor protein binds to the operator region and prevents transcription. When lactose is present, it is converted to allolactose which binds the repressor and prevents it from binding the operator, allowing transcription. The presence of glucose inhibits transcription through a mechanism involving cAMP and the catabolite activator protein.
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Lac operon
Each cell in the human contains all the genetic material for the growth and development of a human
Some of these genes will be need to be expressed all the time
These are the genes that are involved in of vital biochemical processes such as respiration
Other genes are not expressed all the time
They are switched on an off at need
Regulation of lac operon positive nd negative
The document summarizes the regulation of the lac operon in E. coli. It describes how the lac operon can be regulated both positively and negatively in response to the presence of lactose or glucose. In negative regulation, the lac repressor binds to the operator site in the absence of lactose, preventing transcription. In the presence of lactose, it binds to allolactose and dissociates from DNA, allowing transcription. Positive regulation involves cAMP and the catabolite activator protein activating transcription in the absence of glucose.
Lac operon
This is my first presentation share in this platform. Hope this is helpful for you! Here, I have tried to explain MECHANISM OF LAC OPERON in E.Coli in informative and crisp manner with simple language and few images.
Lac operon
Bacteria regulate gene expression through operons, which are groups of functionally related genes that are controlled together. Operons can be regulated positively or negatively in response to environmental conditions. The lac operon in E. coli controls the transport and metabolism of lactose and consists of structural genes regulated by a promoter, terminator, and repressor. The lac operon is negatively regulated - the lac repressor normally binds the operator to prevent transcription, but is released when bound by the inducer allolactose, allowing expression. Transcription is also controlled by the availability of glucose and regulated by the catabolite activator protein CAP.
Lac operon concept
Includes definition, discovery.Enzyme induction is a process in which a molecule (e.g., a drug) induces (i.e., initiates or enhances) the expression of an enzyme.
The induction of heat shock proteins in the fruit fly Drosophila melanogaster.
The Lac operon is an interesting example of how gene expression can be regulated.
Viruses, despite having only a few genes, possess mechanisms to regulate their gene expression, typically into an early and late phase, using collinear systems regulated by anti-terminators (lambda phage) or splicing modulators (HIV).
Gal4 is a transcriptional activator that controls the expression of GAL1, GAL7, and GAL10 (all of which code for the metabolic of galactose in yeast). The GAL4/UAS system has been used in a variety of organisms across various phyla to study gene expression.
Lac operon
The document summarizes the lac operon which regulates lactose metabolism in E. coli bacteria. The lac operon consists of structural genes that encode enzymes for lactose breakdown. It is regulated by the lac repressor protein which binds to the operator region in the absence of lactose to prevent transcription. In the presence of lactose, the repressor detaches from the operator allowing transcription. A second control involves the catabolite activator protein (CAP) and cyclic AMP (cAMP) which activate transcription in the absence of glucose. The mechanism of induction and classification of regulatory mutants are also described.
Lac operon
The operon theory proposes that genes are organized into operons - clusters of genes under the control of a single promoter. An operon contains a promoter, operator, and multiple structural genes. The lac operon in E. coli regulates genes involved in lactose metabolism. It is negatively regulated - in the absence of lactose, a repressor binds the operator to prevent transcription, but lactose or allolactose induce transcription by binding to the repressor. The operon theory explains how bacteria regulate gene expression in response to environmental conditions.
Lac operon system
This presentation will give an introduction to operon and to its history. And gives a detailed or brief explanation about lac operon, its gene composition , their functions, its working mechanism and the use of lac operon in molecular biology.
Lac Operon for class 12th
The document discusses gene regulation and the lac operon. It describes the lac operon as having structural genes, an operator, and a promoter that are required for gene expression. The lac operon was first defined in studies of lactose metabolism in E. coli. It introduced the terms "operon" and "operator" and showed that a regulatory gene encodes a repressor that binds to the operator to control transcription of the structural genes in response to the presence or absence of an inducer molecule like lactose.
Lac operon (1)
The regulation of gene expression is critical for all organisms. There are two main types of genes - constitutive genes that are always "on" and non-constitutive or luxury genes that are regulated. Gene regulation involves turning genes on and off through transcriptional and translational control. Key elements that regulate genes include regulatory genes, structural genes, and regulatory elements in DNA that control transcription. Regulation can occur at the level of DNA, transcription, mRNA processing, translation, and post-translation. The lac operon in E. coli is an example of negative inducible gene regulation involving a repressor, operator, and inducer to control lactose metabolism genes.
Lac Operon
The document summarizes the lac operon in E. coli, which allows the bacteria to transport and metabolize lactose. The lac operon is made up of three coding regions that are regulated by a promoter, operator, and terminator. It is environmentally regulated, meaning the presence of lactose affects whether or not the genes are expressed. Specifically, lactose binds to the LacI repressor, preventing it from blocking RNA polymerase and allowing expression of the lac genes and digestion of lactose.
Gene regulation in prokaryotes
A gene is basic unit of heredity and a sequence of nucleotides in DNA that Encodes synthesis of Gene product either RNA
operon concept
The document discusses operons, which are groups of prokaryotic genes that are transcribed together to serve a single purpose. Jacob and Monod discovered the operon concept in 1961 while studying E. coli metabolism. An operon contains an operator, promoter, and genes. Regulatory proteins can control operon transcription by repressing or inducing it. Examples discussed include the lac and trp operons, which use different mechanisms of negative and positive induction/repression to control gene expression based on environmental conditions.
6ed68c 20110926 chapter26-outline
The operon is a unit of bacterial gene expression that includes structural genes and control elements in DNA. The lac operon is an example of negative inducible regulation, where a repressor protein binds to the operator to prevent transcription unless the inducer is present. The lac repressor is a tetramer controlled by allosteric changes - binding of the inducer inactivates the repressor. Other operons like trp use different mechanisms of regulation including attenuation, where transcription is controlled by RNA secondary structure formation. Translation can also be regulated through features in the 5' UTR of mRNAs.
Ara operon
The document summarizes the ara operon, which regulates genes involved in the metabolism of arabinose sugar. It consists of 3 key components: structural genes that encode enzymes for arabinose catabolism, an operator site that binds a repressor protein, and a promoter that enables transcription. Specifically, the ara operon contains 3 structural genes - araB, araA, araD - that code for enzymes converting arabinose into an intermediate. It is regulated by the araC gene product, which can act as both a repressor and activator depending on arabinose and glucose levels. When arabinose is low and glucose high, the araC repressor binds the operator sites, forming a DNA loop that
Lac operon
The lac operon contains three genes - lacZ, lacY, and lacA - that are transcribed together and encode proteins involved in lactose metabolism. The operon contains regulatory sequences including a promoter where RNA polymerase binds, an operator where the lac repressor binds to block transcription, and a CAP binding site where the catabolite activator protein binds to promote transcription when glucose levels are low. The lac operon is expressed only when lactose is present and glucose is absent, regulated by the lac repressor and CAP in response to lactose and glucose levels.
Lac operon
The lac operon controls the breakdown of lactose in E. coli bacteria. It consists of three structural genes (lacZ, lacY, lacA) that are regulated by a single promoter and operator region. In the absence of lactose, a lac repressor binds to the operator, preventing transcription of the structural genes. When lactose is present, it binds to the repressor and causes a conformational change, releasing it from the operator and allowing transcription. Mutations in the operator, structural genes, or promoter region provided insights into the operon's control mechanism.
Regulation of gene expression
This document discusses the regulation of gene expression. It defines key terms like gene, genome, and gene expression. It explains that some genes are expressed continuously while others are only expressed under certain conditions. There are mechanisms that allow cells to express or turn off certain genes as needed. Regulation of gene expression is essential for optimal energy use and the growth, development, and existence of organisms. There are two main types of regulation: positive regulation which increases gene expression, and negative regulation which decreases it. The document then focuses on prokaryotic gene expression, explaining operons as groups of genes expressed together from a single promoter. It provides the example of the lac operon in E. coli, which expresses genes for lactose metabolism
Lac Operon
The document summarizes gene regulation in prokaryotes and eukaryotes. In prokaryotes, genes are organized into operons that are regulated by repressor or inducible systems like the tryptophan and lactose operons. The tryptophan operon is turned off by a repressor when tryptophan levels are high. The lactose operon is induced when lactose is present and glucose levels are low. In eukaryotes, gene expression is controlled through chromatin structure, pre-transcriptional and post-transcriptional regulation involving transcription factors and RNA processing, and pre-translational and post-translational regulation involving translation initiation, protein processing and degradation.
Operon
This document provides an overview of gene regulation in prokaryotes using the lac operon in E. coli as an example. It explains that genes are regulated to control which proteins are expressed at different times. The lac operon consists of structural genes that encode enzymes for lactose metabolism, as well as a regulatory gene that produces a repressor protein. In the absence of the lactose inducer, the repressor binds to the operator region and prevents transcription. When lactose is present, it binds to the repressor and causes a conformational change that prevents it from binding to the operator, allowing transcription.
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Similar to lac mutation (gene regulation)
differernt types of Operon concepts
total description of lactose operon, galactose operon, arabinose operon, tryptophan operon and their regulations and mechanisms
LAC OPERON.pptx
The document discusses gene regulation in prokaryotes using the lac operon in E. coli as an example. The lac operon consists of structural genes that encode proteins for lactose metabolism and regulatory genes that control their expression. In the absence of lactose, a repressor protein binds to the operator region and prevents transcription. When lactose is present, it is converted to allolactose which binds the repressor and prevents it from binding the operator, allowing transcription. The presence of glucose inhibits transcription through a mechanism involving cAMP and the catabolite activator protein.
Lac operon overall
The document discusses the lac operon in bacteria. The lac operon is a cluster of genes involved in lactose metabolism. It includes three structural genes that encode enzymes for breaking down lactose. The operon is induced in the presence of lactose and repressed in its absence by a lac repressor protein. The lac operon demonstrates how bacteria efficiently regulate gene expression in response to environmental conditions through an inducible operon system.
GENE REGULATION IN PROKARYOTES AND EUKARYOTES
1. Gene regulation in prokaryotes and eukaryotes involves control at the levels of transcription and translation.
2. In prokaryotes, genes are often organized into operons and regulated through inducible and repressible operons controlled by regulatory proteins binding to operator and promoter sites. The lac and trp operons are examples of inducible and repressible operons, respectively.
3. In eukaryotes, gene expression is controlled through chromatin structure, transcriptional initiation, transcript processing and modification, transport, stability, and small RNA-mediated pathways. This allows for complex tissue-specific and developmental control of gene expression.
The Lac operon
The lac operon controls the breakdown of lactose in E. coli bacteria. It consists of three structural genes (lacZ, lacY, lacA) that are regulated by a single promoter and operator region. In the absence of lactose, a lac repressor binds to the operator, preventing transcription of the structural genes. When lactose is present, it binds to the repressor and causes a conformational change, releasing it from the operator and allowing transcription. Mutations in the operator, structural genes, or promoter region provided insights into the operon's control mechanism.
Operon concept.pdf
The document discusses the operon concept in prokaryotes. It defines an operon as a cluster of genes located together on the chromosome that are transcribed together. Operons contain structural genes whose products work together in a metabolic pathway, as well as a regulatory gene that controls expression of the structural genes. The basic operon structure includes structural genes, an operator site that binds a repressor, and a promoter where RNA polymerase binds. The lac operon codes for enzymes that break down lactose and is induced by the presence of lactose. It contains genes, an operator, and a promoter, as well as the lac repressor gene that produces a repressor protein to block transcription unless lactose is present.
Lac operon slide
Gene regulation can be defined as any kind of alteration in the gene to give rise to a different expression which might result in a change in the synthesized amino acid sequence.”
Gene expression is basically the synthesis of the polypeptide chain encoded by a particular gene.
Therefore the expression of the gene can be quantified in terms of the amount of protein synthesised by the genes.
lac Operon.pdf
1. The lac operon encodes three genes involved in lactose metabolism in E. coli and is regulated by the presence of lactose and glucose.
2. In the absence of lactose, a repressor protein binds to the operator site and blocks transcription of the lac genes.
3. When lactose is present, it binds to the repressor protein causing a conformational change that prevents it from binding to the operator, allowing transcription.
Over view of lac I [inhibitor]
The document discusses the lac operon, which was first described by Francois Jacob and Jacques Monod in 1961. The lac operon includes the lacI gene, which encodes the lac repressor protein. The lac repressor protein regulates the lac operon by binding to the operator region and preventing transcription of the structural genes under normal conditions. When lactose is present, it binds to the lac repressor and causes a conformational change that prevents it from binding to the operator, allowing transcription to occur. The lac repressor is a tetramer protein made up of four identical 360 amino acid subunits with a total molecular weight of around 154,520 Daltons.
OPERONS- KHZ 2023.ppt
The document discusses gene regulation and operons. It covers:
1. Operons are groups of genes transcribed together in prokaryotes to control important processes. The lac operon in E. coli contains genes for lactose metabolism.
2. The lac operon is regulated by a repressor protein that binds to the operator site and blocks transcription unless the inducer allolactose is present.
3. Eukaryotic gene regulation has multiple levels including chromatin remodeling, histone modification through methylation and acetylation, and transcription factor regulation.
Regulation of gene expression in Prokaryotes (Lac Operon).pptx by Muhammad An...
1. The lac operon regulates the expression of genes involved in lactose catabolism in prokaryotes in response to the presence of lactose or glucose.
2. It consists of structural genes that encode enzymes for lactose breakdown and a regulatory gene that produces a repressor protein.
3. In the absence of lactose, the repressor binds to the operator region and prevents transcription of the structural genes. However, in the presence of lactose, it binds to lactose instead, allowing transcription.
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Regulation of Gene Expression in Prokaryotes
Gene expression in prokaryotes is primarily regulated at the transcription initiation step through the use of operons, which contain clusters of genes controlled by a single promoter. Operons include structural genes, operators that repressors can bind to, and promoters where RNA polymerase binds. Key examples like the lac operon are regulated by repressors that bind to the operator in the absence of an inducer, and activators like CAP that help recruit RNA polymerase to initiate transcription.
lac Operon.ppt-2.pptxThe classic example
The classic example of prokaryotic gene regulation is that of the lac operon. This operon is a genetic unit that produces the enzymes necessary for the digestion of lactose (Fig. 16-13). The lac operon consists of three contiguous structural genes that are transcribed as continuous mRNA by RNA polymerase.
lac-Operon.pptx
The document discusses operons and how they control gene expression. An operon is a single transcription unit that contains a promoter, operator, and multiple genes that are functionally related. Operons allow for a single on-off switch to control a cluster of genes. The classic example is the lac operon in E. coli, which contains genes for lactose metabolism. In the absence of lactose, a repressor protein binds to the operator and prevents transcription, but in the presence of lactose the repressor is inactivated and the genes are expressed.
Lac Operon.pdf
The basics of Lactose Operon of prokaryotic cell and its detailed information for students at graduation level. An interesting topic of Molecular Biology. It is mainly for students of Life Science.
LAC OPERON IN E.COLI
The lac operon in E. coli consists of structural genes that code for enzymes involved in lactose metabolism, regulated by a repressor protein. In the absence of the lactose inducer, the repressor binds to the operator region, preventing transcription of the structural genes. However, in the presence of lactose, the inducer binds to the repressor causing a conformational change that prevents it from binding to the operator, allowing transcription and expression of the structural genes. This creates a negative control system where gene expression is turned on by relieving repression through inducer binding.
Negative gene regulation
Gene expression is the process by which information from a gene is used to produce a functional product like a protein. The document discusses gene regulation in E. coli using the lac operon as an example. The lac operon controls lactose metabolism and consists of 3 genes regulated by the lac repressor and catabolite activator protein (CAP). When glucose is present, the lac operon is off, but when glucose is low and lactose available, the operon is strongly expressed to use lactose.
operon_lac_and_trp_in_ bacteria.ppt
Gene expression is tightly regulated through various mechanisms in both prokaryotes and eukaryotes. In prokaryotes, genes are often organized into operons and regulated together. The lac operon in E. coli contains three genes involved in lactose metabolism that are regulated by a repressor protein. In the absence of lactose, the repressor binds to the operator region and blocks transcription. When lactose is present, it is converted to allolactose, which binds to the repressor and causes a conformational change that prevents it from binding to the operator, allowing transcription to proceed. This provides an example of negative and inducible gene regulation.
Similar to lac mutation (gene regulation) (20)
Regulation of gene expression in Prokaryotes (Lac Operon).pptx by Muhammad An...
Regulation of gene expression in Prokaryotes (Lac Operon).pptx by Muhammad An...
l bkomnfdtg9iugnerz89ugojk[xndfgo9i-zsdjnrgfiu9jaSEfjaEWjf8AEUfh8iochem.pptx
l bkomnfdtg9iugnerz89ugojk[xndfgo9i-zsdjnrgfiu9jaSEfjaEWjf8AEUfh8iochem.pptx
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11.1 Role of physical biological in deterioration of grains.pdf
Storagedeteriorationisanyformoflossinquantityandqualityofbio-materials.
Themajorcausesofdeteriorationinstorage
•Physical
•Biological
•Mechanical
•Chemical
Storageonlypreservesquality.Itneverimprovesquality.
Itisadvisabletostartstoragewithqualityfoodproduct.Productwithinitialpoorqualityquicklydepreciates
Quality assurance B.pharm 6th semester BP606T UNIT 5
Warehousing
Good warehousing practices
Material management
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDS
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
Embracing Deep Variability For Reproducibility and Replicability
Embracing Deep Variability For Reproducibility and ReplicabilityUniversity of Rennes, INSA Rennes, Inria/IRISA, CNRS
Embracing Deep Variability For Reproducibility and Replicability
Abstract: Reproducibility (aka determinism in some cases) constitutes a fundamental aspect in various fields of computer science, such as floating-point computations in numerical analysis and simulation, concurrency models in parallelism, reproducible builds for third parties integration and packaging, and containerization for execution environments. These concepts, while pervasive across diverse concerns, often exhibit intricate inter-dependencies, making it challenging to achieve a comprehensive understanding. In this short and vision paper we delve into the application of software engineering techniques, specifically variability management, to systematically identify and explicit points of variability that may give rise to reproducibility issues (eg language, libraries, compiler, virtual machine, OS, environment variables, etc). The primary objectives are: i) gaining insights into the variability layers and their possible interactions, ii) capturing and documenting configurations for the sake of reproducibility, and iii) exploring diverse configurations to replicate, and hence validate and ensure the robustness of results. By adopting these methodologies, we aim to address the complexities associated with reproducibility and replicability in modern software systems and environments, facilitating a more comprehensive and nuanced perspective on these critical aspects.
https://hal.science/hal-04582287
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆
Context. The early-type galaxy SDSS J133519.91+072807.4 (hereafter SDSS1335+0728), which had exhibited no prior optical variations during the preceding two decades, began showing significant nuclear variability in the Zwicky Transient Facility (ZTF) alert stream from December 2019 (as ZTF19acnskyy). This variability behaviour, coupled with the host-galaxy properties, suggests that SDSS1335+0728 hosts a ∼ 106M⊙ black hole (BH) that is currently in the process of ‘turning on’. Aims. We present a multi-wavelength photometric analysis and spectroscopic follow-up performed with the aim of better understanding the origin of the nuclear variations detected in SDSS1335+0728. Methods. We used archival photometry (from WISE, 2MASS, SDSS, GALEX, eROSITA) and spectroscopic data (from SDSS and LAMOST) to study the state of SDSS1335+0728 prior to December 2019, and new observations from Swift, SOAR/Goodman, VLT/X-shooter, and Keck/LRIS taken after its turn-on to characterise its current state. We analysed the variability of SDSS1335+0728 in the X-ray/UV/optical/mid-infrared range, modelled its spectral energy distribution prior to and after December 2019, and studied the evolution of its UV/optical spectra. Results. From our multi-wavelength photometric analysis, we find that: (a) since 2021, the UV flux (from Swift/UVOT observations) is four times brighter than the flux reported by GALEX in 2004; (b) since June 2022, the mid-infrared flux has risen more than two times, and the W1−W2 WISE colour has become redder; and (c) since February 2024, the source has begun showing X-ray emission. From our spectroscopic follow-up, we see that (i) the narrow emission line ratios are now consistent with a more energetic ionising continuum; (ii) broad emission lines are not detected; and (iii) the [OIII] line increased its flux ∼ 3.6 years after the first ZTF alert, which implies a relatively compact narrow-line-emitting region. Conclusions. We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼ 106M⊙ AGN that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGNobserved in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour. Key words. galaxies: active– accretion, accretion discs– galaxies: individual: SDSS J133519.91+072807.4
Direct Seeded Rice - Climate Smart Agriculture
Direct Seeded Rice - Climate Smart AgricultureInternational Food Policy Research Institute- South Asia Office
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
Post translation modification by Suyash Garg
overview of PTM helps to the students who wants to clear their basics about it.
Sustainable Land Management - Climate Smart Agriculture
Sustainable Land Management - Climate Smart AgricultureInternational Food Policy Research Institute- South Asia Office
PPT on Sustainable Land Management presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
Anti-Universe And Emergent Gravity and the Dark Universe
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
Compositions of iron-meteorite parent bodies constrainthe structure of the pr...
Magmatic iron-meteorite parent bodies are the earliest planetesimals in the Solar System,and they preserve information about conditions and planet-forming processes in thesolar nebula. In this study, we include comprehensive elemental compositions andfractional-crystallization modeling for iron meteorites from the cores of five differenti-ated asteroids from the inner Solar System. Together with previous results of metalliccores from the outer Solar System, we conclude that asteroidal cores from the outerSolar System have smaller sizes, elevated siderophile-element abundances, and simplercrystallization processes than those from the inner Solar System. These differences arerelated to the formation locations of the parent asteroids because the solar protoplane-tary disk varied in redox conditions, elemental distributions, and dynamics at differentheliocentric distances. Using highly siderophile-element data from iron meteorites, wereconstruct the distribution of calcium-aluminum-rich inclusions (CAIs) across theprotoplanetary disk within the first million years of Solar-System history. CAIs, the firstsolids to condense in the Solar System, formed close to the Sun. They were, however,concentrated within the outer disk and depleted within the inner disk. Future modelsof the structure and evolution of the protoplanetary disk should account for this dis-tribution pattern of CAIs.
快速办理(UAM毕业证书)马德里自治大学毕业证学位证一模一样
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Alternate Wetting and Drying - Climate Smart Agriculture
Alternate Wetting and Drying - Climate Smart AgricultureInternational Food Policy Research Institute- South Asia Office
PPT on Alternate Wetting and Drying presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024. HUMAN EYE By-R.M Class 10 phy best digital notes.pdf
Class 10 human eye notes physics
Handwritten best quality
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Farming systems analysis: what have we learnt?.pptx
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Introduction_Ch_01_Biotech Biotechnology course .pptx
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11.1 Role of physical biological in deterioration of grains.pdf
11.1 Role of physical biological in deterioration of grains.pdf
Quality assurance B.pharm 6th semester BP606T UNIT 5
Quality assurance B.pharm 6th semester BP606T UNIT 5
Embracing Deep Variability For Reproducibility and Replicability
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lac mutation (gene regulation)
- 1. GENE REGULATION Created by :- Gaurav Pathak DEPARTMENT OF MICROBIOLOGY
- 2. 0peron • Identified by Francois Jacob and Jacques Monod in 1961 • Unit of coordinate gene expression • Its includes structural genes and their adjacent regulatory elements • In some situations multiple operons are controlled by the same regulatory protein known as REGULON • TYPES - Lac operon - Ara operon - Trp operon (repressible) inducible
- 4. Two types of Negative Gene Regulation Repressible operon - binding of a specific repressor protein to the operator shuts of transcription inducible operon - binding of an inducer to an innately inactive repressor inactivates the the repressor and turns on transcription
- 5. Lac mutation constitutive mutation :- A mutant, in which structural genes of an operon are always transcribed, even in the absence of inducer • Comman iin negatively regulated operons Uninducible mutation :-The expression of lac operon genes cannot be induced
- 6. Lac operon mutants Genotype Nature lacZ Null mutation in lacZ lacY Null mutation in lacY lacO lacO can`t bind repressor; constitutive (always on ) lacP Promoter cannot bind RNA polymerase; operon not transcribed lacIs Repressor cant bind inducer; super-repressor
- 7. The partial diploid lacI+ lacZ //lacI+ lacZ+ produces β-galactosidase only in the presence of lactose because the lacI gene is trans dominant
- 8. The partial diploid lacIs lacZ+/lacI+lacZ+ fails to produce β-galactosidase in the prensence and absence of lactose because the lacIs gene encodes a superrepressor.
- 9. Mutaion in lacO are constitutive
- 11. Gratuitous Inducer • A gratuitous inducer is a molecule which is structurally similar to another molecule that induces transcription for a specific product when the official inducer is absent. • IPTG (Isopropyl β-D-1 thiogalactopyranoside) is a molecular biology reagent. • This compound is a molecular mimic of allolactse, a lactose metabolite that triggers transcription of the lac operon and it is there for used to induce protein expression where the gene under the control of the lac operator