Transcriptional Control
... A. Structural Genes: The sequence of genes required to produce the desired product. Many are part of the same metabolic pathway and are in a specific order. ...
... A. Structural Genes: The sequence of genes required to produce the desired product. Many are part of the same metabolic pathway and are in a specific order. ...
Viral Lytic and Lysogenic Cycles
... surface of a host bacterium, such as E. coli. The phage injects its DNA into the host cell, leaving the empty protein coat outside. The DNA of the host cell is __________________, and host cell enzymes and nucleotides are commandeered to __________________ the phage DNA, making more phage DNA. The h ...
... surface of a host bacterium, such as E. coli. The phage injects its DNA into the host cell, leaving the empty protein coat outside. The DNA of the host cell is __________________, and host cell enzymes and nucleotides are commandeered to __________________ the phage DNA, making more phage DNA. The h ...
The central premise of Nevo is that the adaptation of
... The chapter titles in this monograph whet the appetite for a volume that covers the subject from conception to current analyses of pathogenic bacteria. An instructive, historical perspective from the editor prefaces three foundation chapters concerned with the recognition of speci®c DNA- and RNAbind ...
... The chapter titles in this monograph whet the appetite for a volume that covers the subject from conception to current analyses of pathogenic bacteria. An instructive, historical perspective from the editor prefaces three foundation chapters concerned with the recognition of speci®c DNA- and RNAbind ...
File
... protein must be activated to stop transcription. Tryptophan is an amino acid needed by E. coli and the ...
... protein must be activated to stop transcription. Tryptophan is an amino acid needed by E. coli and the ...
Control of Gene Expression
... • Post-transcriptional Control: editing of exons • Translational Control – Involves whether or not m-RNA is used or stored in cytoplasm • Ex., egg cells often with large amounts of m-RNA “ready for use” ...
... • Post-transcriptional Control: editing of exons • Translational Control – Involves whether or not m-RNA is used or stored in cytoplasm • Ex., egg cells often with large amounts of m-RNA “ready for use” ...
lac
... • Cancer results from genes that do not turn off properly. Cancer cells have lost their ability to regulate mitosis, resulting in uncontrolled cell division ...
... • Cancer results from genes that do not turn off properly. Cancer cells have lost their ability to regulate mitosis, resulting in uncontrolled cell division ...
Regulation
... control is mediated by low molecular substances that are either synthesized by the cell or present in the environment. These low MW molecules, called EFFECTOR MOLECULES or ligands, interact with specific protein molecules, called ALLOSTERIC PROTEINS, and alter the properties of these proteins, i.e., ...
... control is mediated by low molecular substances that are either synthesized by the cell or present in the environment. These low MW molecules, called EFFECTOR MOLECULES or ligands, interact with specific protein molecules, called ALLOSTERIC PROTEINS, and alter the properties of these proteins, i.e., ...
Gene Regulation = Control of Gene Expression Dr. A. Abouelmagd
... Translation results in separate 3 enzymes, because: Each enzyme is marked by initiation and termination codons on mRNA. 1) Permease ...
... Translation results in separate 3 enzymes, because: Each enzyme is marked by initiation and termination codons on mRNA. 1) Permease ...
Central Dogma of Molecular Biology
... LacY codes for ß-galactosidase permease LacA codes for thiogalactoside transcyclase When lactose is unavailable as a carbon source, the lac operon is not transcribed ...
... LacY codes for ß-galactosidase permease LacA codes for thiogalactoside transcyclase When lactose is unavailable as a carbon source, the lac operon is not transcribed ...
Regulation-of-Gene
... achieved by a single operator site that regulates two promoters facing in opposite directions In one example, the genes ilvC (coding for an enzyme needed for isoleucine and valine biosynthesis) and ilvY (which codes for a regulatory protein) are transcribed in opposite directions , but transcription ...
... achieved by a single operator site that regulates two promoters facing in opposite directions In one example, the genes ilvC (coding for an enzyme needed for isoleucine and valine biosynthesis) and ilvY (which codes for a regulatory protein) are transcribed in opposite directions , but transcription ...
Saturday Study Session 2 Theme of the day: Information Transfer
... Polymerase Chain Reaction (PCR) ...
... Polymerase Chain Reaction (PCR) ...
F4-6 Gene Regulation and Mutation Ch12,13
... a. Section of DNA that contains genes needed to produce particular proteins b. Operon responds to changes in environment 3. Parts of an operon a. Operator – segment of DNA that acts as on/off switch for transcription b. Promotor – section of DNA where RNA 1st binds c. Regulatory gene – makes repress ...
... a. Section of DNA that contains genes needed to produce particular proteins b. Operon responds to changes in environment 3. Parts of an operon a. Operator – segment of DNA that acts as on/off switch for transcription b. Promotor – section of DNA where RNA 1st binds c. Regulatory gene – makes repress ...
Control of gene expression in prokaryotes and eukaryotes
... Prokaryotic control mechanisms Bacteria sometimes have multiple genes under the control of one promoter. This series of genes is called an operon. There are different mechanisms for controlling operons, but one is called the inducible operon. Three different polypeptides are needed to make lactase i ...
... Prokaryotic control mechanisms Bacteria sometimes have multiple genes under the control of one promoter. This series of genes is called an operon. There are different mechanisms for controlling operons, but one is called the inducible operon. Three different polypeptides are needed to make lactase i ...
Gene Regulation Topic Guide
... digest lactose. If it is on, lactose can be digested. First, draw the lac operon. 14. How many genes does the lac operon have? 15. What is the function of the operon? 16. What is the function of the repressor? 17. Why is this called positive control? 18. What happens to the lac operon when lactose ...
... digest lactose. If it is on, lactose can be digested. First, draw the lac operon. 14. How many genes does the lac operon have? 15. What is the function of the operon? 16. What is the function of the repressor? 17. Why is this called positive control? 18. What happens to the lac operon when lactose ...
Judgement Statement – 2012
... proteins / enzymes. Describes the overall role / importance of the operon. Eg, the operon allows bacteria to break down lactose when it is present. Eg, important for conservation of energy for bacterium. ...
... proteins / enzymes. Describes the overall role / importance of the operon. Eg, the operon allows bacteria to break down lactose when it is present. Eg, important for conservation of energy for bacterium. ...
Schedule
... proteins / enzymes. Describes the overall role / importance of the operon. Eg, the operon allows bacteria to break down lactose when it is present. Eg, important for conservation of energy for bacterium. ...
... proteins / enzymes. Describes the overall role / importance of the operon. Eg, the operon allows bacteria to break down lactose when it is present. Eg, important for conservation of energy for bacterium. ...
Coarse-Graining of Macromolecules
... The goal: compute the probability of promoter occupancy as a ratio of promoter occupied states to all of the states available to all of the polymerase molecules. Number of ways of arranging the polymerase molecules is a classic problem in statistics. ...
... The goal: compute the probability of promoter occupancy as a ratio of promoter occupied states to all of the states available to all of the polymerase molecules. Number of ways of arranging the polymerase molecules is a classic problem in statistics. ...
Chapter 7A
... The E. coli lac Operon The control of gene expression by transcription activation and repression has been studied extensively in bacteria. As an example, the E. coli lac operon, which encodes 3 genes (lacZYA) involved in lactose metabolism, uses both mechanisms of control (Fig. 7.3). A specific rep ...
... The E. coli lac Operon The control of gene expression by transcription activation and repression has been studied extensively in bacteria. As an example, the E. coli lac operon, which encodes 3 genes (lacZYA) involved in lactose metabolism, uses both mechanisms of control (Fig. 7.3). A specific rep ...
Gene expression
... Mechanisms of Positive Control: Catabolite Repression • Transcription of the lac operon is greatly reduced when glucose is present, even when lactose is also available. – When glucose is already available, the cell does not need to produce more by cleaving lactose. • This is an example of catabolit ...
... Mechanisms of Positive Control: Catabolite Repression • Transcription of the lac operon is greatly reduced when glucose is present, even when lactose is also available. – When glucose is already available, the cell does not need to produce more by cleaving lactose. • This is an example of catabolit ...
The control of gene expression
... Which form the repressor assumes depends upon cues from a metabolite Both systems are thus examples of negative control Binding of active repressor to an operator always turns off structural gene expression. The lac operon is a system with negative control, because allolactose does not interac ...
... Which form the repressor assumes depends upon cues from a metabolite Both systems are thus examples of negative control Binding of active repressor to an operator always turns off structural gene expression. The lac operon is a system with negative control, because allolactose does not interac ...
Gene Regulation
... that would turn on all the genes in a pathway at one time using 2 enhancer sequences and 2 activator proteins but does not turn on more than one pathway at a time? specific combinations of transcription factors could be used to regulate a group of genes for a given pathway. Using combinations of a ...
... that would turn on all the genes in a pathway at one time using 2 enhancer sequences and 2 activator proteins but does not turn on more than one pathway at a time? specific combinations of transcription factors could be used to regulate a group of genes for a given pathway. Using combinations of a ...
Operon
... Levels (cont’d) Transcriptional gene regulation Regulation of which genes are transcribed Can involve control of the rate at which transcription occurs Posttranscriptional gene regulation Modifications made to primary transcript in the nucleus ...
... Levels (cont’d) Transcriptional gene regulation Regulation of which genes are transcribed Can involve control of the rate at which transcription occurs Posttranscriptional gene regulation Modifications made to primary transcript in the nucleus ...
Operons
... The co-repressor is the amino acid tryptophan. Thus, when tryptophan is abundant, the repressor is active and will bind to the Operator, preventing transcription of these genes. But if tryptophan levels fall, the repressor will lose its trp co-repressor and will fall off the Operator, and the genes ...
... The co-repressor is the amino acid tryptophan. Thus, when tryptophan is abundant, the repressor is active and will bind to the Operator, preventing transcription of these genes. But if tryptophan levels fall, the repressor will lose its trp co-repressor and will fall off the Operator, and the genes ...
Study Guide
... and refers you to Box 1 for details. We will explore Box 1 in a parallel assignment using TeraSim software; for now, focus on the equations for dmi/dt and dpi/dt, the changes in mRNA and protein concentrations, respectively, over time. The equation for dmi/dt shows that mRNA is degraded at a rate pr ...
... and refers you to Box 1 for details. We will explore Box 1 in a parallel assignment using TeraSim software; for now, focus on the equations for dmi/dt and dpi/dt, the changes in mRNA and protein concentrations, respectively, over time. The equation for dmi/dt shows that mRNA is degraded at a rate pr ...
Gene expression
... lac operon • The group do 3 genes (lac Z, lac Y, lacA) MUST be turned on before the bacterium can use lactose as food. • When lactose is not present in the bacterium’s environment, the repressor binds to the operator. • The protein blocks the movement of RNA polymerase along the DNA, and the operon ...
... lac operon • The group do 3 genes (lac Z, lac Y, lacA) MUST be turned on before the bacterium can use lactose as food. • When lactose is not present in the bacterium’s environment, the repressor binds to the operator. • The protein blocks the movement of RNA polymerase along the DNA, and the operon ...
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.