PowerPoint 簡報
... Cooperative binding and allostery have many roles in gene regulation • Simple cooperative binding: the activator interacts simultaneously with DNA and with polymerase and so recruits the enzyme to the promoter. • Allostery is not only a mechanism of gene activation, it is also often the way regulat ...
... Cooperative binding and allostery have many roles in gene regulation • Simple cooperative binding: the activator interacts simultaneously with DNA and with polymerase and so recruits the enzyme to the promoter. • Allostery is not only a mechanism of gene activation, it is also often the way regulat ...
Presentation
... from heterochromatin to euchromatin by chemically modifying histones (proteins associated with DNA to form nucleosomes) ...
... from heterochromatin to euchromatin by chemically modifying histones (proteins associated with DNA to form nucleosomes) ...
lac
... -eg. negative or positive regulator -mutations cannot be -mutations can be complemented complemented -mutations may be recessive or -mutations may be recessive or dominant dominant regulatory proteins are trans-acting factors that recognize cisacting elements to control gene expression ...
... -eg. negative or positive regulator -mutations cannot be -mutations can be complemented complemented -mutations may be recessive or -mutations may be recessive or dominant dominant regulatory proteins are trans-acting factors that recognize cisacting elements to control gene expression ...
Note 7.4 - Controlling Gene Expression
... Posttranslational: before many proteins become functional, they must pass through the cell membrane. A number of control mechanisms affect the rate at which a protein becomes active and the time it remains functional, including the addition of various chemical groups. ...
... Posttranslational: before many proteins become functional, they must pass through the cell membrane. A number of control mechanisms affect the rate at which a protein becomes active and the time it remains functional, including the addition of various chemical groups. ...
Prokaryotic Gene Regulation
... – E. coli uses glucose first, and catabolite repression prevents the use of lactose – When glucose is depleted, catabolite repression is alleviated, and the lac operon is expressed ...
... – E. coli uses glucose first, and catabolite repression prevents the use of lactose – When glucose is depleted, catabolite repression is alleviated, and the lac operon is expressed ...
Operon Models
... 5. Using a permanent pen draw the shape of the active form of the repressor protein onto the lower portion of the noodle in the operator region. Make the shape simple, like the one in the diagram, since you will need to carve it out using a serrated knife. Also, carve a matching shape into the regul ...
... 5. Using a permanent pen draw the shape of the active form of the repressor protein onto the lower portion of the noodle in the operator region. Make the shape simple, like the one in the diagram, since you will need to carve it out using a serrated knife. Also, carve a matching shape into the regul ...
Welcome to Our Microbial Genetics Class
... A controlling factor can either inhibit or activate transcription. Although the responses to the presence of metabolites are different, both induction and repression are forms of negative control: mRNA synthesis proceeds more rapidly in the absence of the active controlling factor. The rate of mRNA ...
... A controlling factor can either inhibit or activate transcription. Although the responses to the presence of metabolites are different, both induction and repression are forms of negative control: mRNA synthesis proceeds more rapidly in the absence of the active controlling factor. The rate of mRNA ...
Prok and Euk Gene Expression
... iii. Then 2 makes hairpin with 3 – anti-terminator iv. 3 is not around to bind with 4 to make intrinsic terminator. v. RNA polymerase continues transcribing the remainder of the trp operon. e. When tryptofan levels are high i. Ribosome that is translating the sequence goes through the trp sequence q ...
... iii. Then 2 makes hairpin with 3 – anti-terminator iv. 3 is not around to bind with 4 to make intrinsic terminator. v. RNA polymerase continues transcribing the remainder of the trp operon. e. When tryptofan levels are high i. Ribosome that is translating the sequence goes through the trp sequence q ...
Biology 303 EXAM II 3/14/00 NAME
... C. transposons or transposon-like elements. D. satellite sequences. 40. Based on the sequencing of Craig Venter’s diploid genome, researchers have determined that A. genomes of different individuals are even more similar than previously thought B. genomes of different individuals display greater div ...
... C. transposons or transposon-like elements. D. satellite sequences. 40. Based on the sequencing of Craig Venter’s diploid genome, researchers have determined that A. genomes of different individuals are even more similar than previously thought B. genomes of different individuals display greater div ...
Practice Exam 2
... 1. frame shift early in coding gene mutation. Each type of mutation will be used once. sequence ______ Repressor protein A: has normal protein sequence 2. silent mutation in 4th codon ______ Repressor protein B: cannot bind lactose, but it 3. Single amino acid change can bind the operator (missense) ...
... 1. frame shift early in coding gene mutation. Each type of mutation will be used once. sequence ______ Repressor protein A: has normal protein sequence 2. silent mutation in 4th codon ______ Repressor protein B: cannot bind lactose, but it 3. Single amino acid change can bind the operator (missense) ...
Gene regulation in bacteria -
... sugar arabinose and another group of three genes that are needed to absorb and metabolise lactose. hence the groups of genes above are called the ‘tryptophan operon’, the ‘arabinose operon’ and the ‘lactose (or Lac) operon’. In eukaryotes, in contrast, there are no ‘operons’ — every gene has its own ...
... sugar arabinose and another group of three genes that are needed to absorb and metabolise lactose. hence the groups of genes above are called the ‘tryptophan operon’, the ‘arabinose operon’ and the ‘lactose (or Lac) operon’. In eukaryotes, in contrast, there are no ‘operons’ — every gene has its own ...
Chapter 18~Regulaton of Gene Expression
... if bacterium has enough tryptophan then it doesn’t need to make enzymes used to build tryptophan • turn genes ON example if bacterium encounters new sugar (energy source), like lactose, then it needs to start making enzymes used to digest lactose ...
... if bacterium has enough tryptophan then it doesn’t need to make enzymes used to build tryptophan • turn genes ON example if bacterium encounters new sugar (energy source), like lactose, then it needs to start making enzymes used to digest lactose ...
gene
... • Promoter mutations • lacP−: cis acting • lacI+lacP−lacZ+ / lacI+lacP+lacZ− fails to produce functional β-galactosidase. ...
... • Promoter mutations • lacP−: cis acting • lacI+lacP−lacZ+ / lacI+lacP+lacZ− fails to produce functional β-galactosidase. ...
Gene Regulation - Cloudfront.net
... a promotor region where RNA polymerase first binds an operator region between the promotor and the first gene which acts as an “on-off switch”. ...
... a promotor region where RNA polymerase first binds an operator region between the promotor and the first gene which acts as an “on-off switch”. ...
Poster - Myers Lab
... can track single cells for many generations and measure their expression levels while exposing them to various changing conditions. In a first step we plan to use this device to study the regulation of the lac operon. The device allows us to use the natural inducer of the system while many other stu ...
... can track single cells for many generations and measure their expression levels while exposing them to various changing conditions. In a first step we plan to use this device to study the regulation of the lac operon. The device allows us to use the natural inducer of the system while many other stu ...
Biol115_2014_Lecture 10_Prokaryotic Gene Regulation
... Lac repressor, changing its conformation so that it can no longer bind the operator. This allows RNA polymerase to transcribe the structural genes. ...
... Lac repressor, changing its conformation so that it can no longer bind the operator. This allows RNA polymerase to transcribe the structural genes. ...
Chapter 19 Regulation of Gene Expression in Prokaryotes and Their
... The repressor gene encodes a repressor. The repressor binds (under appropriate conditions) to the operator. Binding is regulated by the presence or absence of the effector molecule (inducer or co-repressor). The promoter is the site of transcription initiation for the structural gene(s). Trans ...
... The repressor gene encodes a repressor. The repressor binds (under appropriate conditions) to the operator. Binding is regulated by the presence or absence of the effector molecule (inducer or co-repressor). The promoter is the site of transcription initiation for the structural gene(s). Trans ...
Lecture Slides - METU Computer Engineering
... •Assembled only when there is an environmental need for motility •Built in an efficient and precise temporal order ...
... •Assembled only when there is an environmental need for motility •Built in an efficient and precise temporal order ...
Operon Info_pGLO pre lab
... binding to the operator and blocking RNA polymerase The repressor is the product of a separate regulatory gene Repressors are often made continuously by the cell, at low levels © 2014 Pearson Education, Inc. ...
... binding to the operator and blocking RNA polymerase The repressor is the product of a separate regulatory gene Repressors are often made continuously by the cell, at low levels © 2014 Pearson Education, Inc. ...
A Discovery Laboratory Investigating Bacterial Gene Regulation
... 5. How long does it take for the cell to respond to new lactose in its environment? Make sure you take time points out to 85 minutes. Negative control = 0 minutes. 6. How does temperature alter the enzyme reaction rate? Make two tubes for each temperature: experimental, and negative control [either ...
... 5. How long does it take for the cell to respond to new lactose in its environment? Make sure you take time points out to 85 minutes. Negative control = 0 minutes. 6. How does temperature alter the enzyme reaction rate? Make two tubes for each temperature: experimental, and negative control [either ...
PGLO Transformation LAB AP LAB 7
... •Place foam rack with + and – tubes on desktop •Use new sterile pipette to add 250 µL Luria broth to + tube •Use new sterile pipette to add 250 µL Luria broth to – tube ...
... •Place foam rack with + and – tubes on desktop •Use new sterile pipette to add 250 µL Luria broth to + tube •Use new sterile pipette to add 250 µL Luria broth to – tube ...
Control of Gene Expression
... • The trp operon is negatively regulated by the trp repressor protein – trp repressor binds to the operator to block transcription – binding of repressor to the operator requires a corepressor which is ...
... • The trp operon is negatively regulated by the trp repressor protein – trp repressor binds to the operator to block transcription – binding of repressor to the operator requires a corepressor which is ...
CHAPTER 18 LECTURE NOTES: CONTROL OF GENE
... 3. The enzyme lactose permease transports lactose into the cell and is encoded by the lacY gene. 4. The genes are transcribed from a polycistronic mRNA along with the lacA gene. 5. There is a promoter region that controls lac expression. 6. There is an operator region to which a repressor binds (see ...
... 3. The enzyme lactose permease transports lactose into the cell and is encoded by the lacY gene. 4. The genes are transcribed from a polycistronic mRNA along with the lacA gene. 5. There is a promoter region that controls lac expression. 6. There is an operator region to which a repressor binds (see ...
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.