university of oslo
... metabolizes first one of the sugars and uses the second sugar only when the first sugar is used up. Diauxie is visible in a two step growth curve corresponding to the use of the two sugars (Figure 14.7). Example: the use of glucose and lactose by E. coli. Glucose indirectly prevents binding of the c ...
... metabolizes first one of the sugars and uses the second sugar only when the first sugar is used up. Diauxie is visible in a two step growth curve corresponding to the use of the two sugars (Figure 14.7). Example: the use of glucose and lactose by E. coli. Glucose indirectly prevents binding of the c ...
Exam V2002 - English
... metabolizes first one of the sugars and uses the second sugar only when the first sugar is used up. Diauxie is visible in a two step growth curve corresponding to the use of the two sugars (Figure 14.7). Example: the use of glucose and lactose by E. coli. Glucose indirectly prevents binding of the c ...
... metabolizes first one of the sugars and uses the second sugar only when the first sugar is used up. Diauxie is visible in a two step growth curve corresponding to the use of the two sugars (Figure 14.7). Example: the use of glucose and lactose by E. coli. Glucose indirectly prevents binding of the c ...
GENETIC CONTROL MECHANISMS AND …
... Not all proteins are needed all the time in cells i.e. Insulin is only required when glucose levels are ____________ in the blood Genes that are constantly expressed are called ______________________________ Gene regulation is vital to an organism’s survival ...
... Not all proteins are needed all the time in cells i.e. Insulin is only required when glucose levels are ____________ in the blood Genes that are constantly expressed are called ______________________________ Gene regulation is vital to an organism’s survival ...
RNA polymerase I
... • The trp operon is an example of a repressible operon, one that is inhibited when a specific small molecule binds allosterically to a regulatory protein. • In contrast, an inducible operon is stimulated when a specific small molecule interacts with a regulatory protein. – In inducible operons, the ...
... • The trp operon is an example of a repressible operon, one that is inhibited when a specific small molecule binds allosterically to a regulatory protein. • In contrast, an inducible operon is stimulated when a specific small molecule interacts with a regulatory protein. – In inducible operons, the ...
IPTG_09-10_8h
... Five hours before you started your experiment we diluted cells from an LB overnight culture into minimal media in the presence of different concentrations of IPTG. This particular minimal media has salts, a carbon source and some amino acids. We also prepared agar pads now made with PBS (phosphate b ...
... Five hours before you started your experiment we diluted cells from an LB overnight culture into minimal media in the presence of different concentrations of IPTG. This particular minimal media has salts, a carbon source and some amino acids. We also prepared agar pads now made with PBS (phosphate b ...
E. coli
... Monod’s early work-diauxie Type A sugarsNo diauxie. We will call them primary sugars (1o) ...
... Monod’s early work-diauxie Type A sugarsNo diauxie. We will call them primary sugars (1o) ...
Bacterial Transformation with pGlo Overview
... • The araPBAD promoter is often used in expression vectors • The pGlo plasmid has been modified to incorporate some features of the arabinose operon. • Both the araPBAD promoter and the araC gene are present. • The genes which code for araA, araB and araD have been replaced by the gene which codes f ...
... • The araPBAD promoter is often used in expression vectors • The pGlo plasmid has been modified to incorporate some features of the arabinose operon. • Both the araPBAD promoter and the araC gene are present. • The genes which code for araA, araB and araD have been replaced by the gene which codes f ...
Gene Regulation Is Necessary
... The repressor protein is produced by a regulator gene. The region of DNA where the repressor protein binds is the operator site. The promoter site is a region of DNA where RNA polymerase can bind. The entire unit (promoter, operator, and genes) is an operon. The lac operon is an example of an induc ...
... The repressor protein is produced by a regulator gene. The region of DNA where the repressor protein binds is the operator site. The promoter site is a region of DNA where RNA polymerase can bind. The entire unit (promoter, operator, and genes) is an operon. The lac operon is an example of an induc ...
Answers to End-of-Chapter Questions – Brooker et al ARIS site
... their hypotheses regarding the lacI gene and the regulation of the lac operon? Answer: The first observation was the presence of some bacterial strains that had constitutive expression of the lac operon. Normally, the genes are only expressed when lactose is present. These mutant strains expressed t ...
... their hypotheses regarding the lacI gene and the regulation of the lac operon? Answer: The first observation was the presence of some bacterial strains that had constitutive expression of the lac operon. Normally, the genes are only expressed when lactose is present. These mutant strains expressed t ...
lac
... lacY lacA Its own promoter and encodes a repressor DNA protein. Transcription It is not part of the operon mRNA ...
... lacY lacA Its own promoter and encodes a repressor DNA protein. Transcription It is not part of the operon mRNA ...
Eukaryotic Expression 1
... Other enzymes in the lac system lactose permease (LacY) acetylase (LacA) ...
... Other enzymes in the lac system lactose permease (LacY) acetylase (LacA) ...
Unit VII Study Guide KEY
... _lactose_____ is present, it binds to the repressor and renders it _dysfunctional___, allowing transcription to proceed. A(n) _repressible____ operon, on the other hand, is normally on. Therefore, its repressor is synthesized in a _dysfunctional_______ form. An example is the _trp____ operon. When _ ...
... _lactose_____ is present, it binds to the repressor and renders it _dysfunctional___, allowing transcription to proceed. A(n) _repressible____ operon, on the other hand, is normally on. Therefore, its repressor is synthesized in a _dysfunctional_______ form. An example is the _trp____ operon. When _ ...
The Operon 操縱元
... Small molecules that induce an operon are identical with or related to the substrate for its enzymes. β-galactosides are the substrates for the enzymes coded by ...
... Small molecules that induce an operon are identical with or related to the substrate for its enzymes. β-galactosides are the substrates for the enzymes coded by ...
Lecture#5 - Introduction to gene regulation and operons in
... It is called a Constitutive mutant - always "on" - expressed - unregulated by inducers. Genetically mapped close to, but distinct from, the ZYA genes ...
... It is called a Constitutive mutant - always "on" - expressed - unregulated by inducers. Genetically mapped close to, but distinct from, the ZYA genes ...
Lab 9: Regulation of lactose metabolism
... The repressor protein has two binding sites— one is for binding the DNA of the operator site, the other is specific for binding galactoside molecules (lactose molecules and other galactosides that are analogs of lactose). As long as there is no lactose in the cell media, the repressor protein remai ...
... The repressor protein has two binding sites— one is for binding the DNA of the operator site, the other is specific for binding galactoside molecules (lactose molecules and other galactosides that are analogs of lactose). As long as there is no lactose in the cell media, the repressor protein remai ...
Regulation of Gene Transcription
... We have already seen the importance of regulatory sites, it is not unsurprising to imagine the problems that could happen were they to be mutated When the regulatory elements of one gene are moved to another by mutations there can be great consequences In development we see this a lot, while such an ...
... We have already seen the importance of regulatory sites, it is not unsurprising to imagine the problems that could happen were they to be mutated When the regulatory elements of one gene are moved to another by mutations there can be great consequences In development we see this a lot, while such an ...
Bioinformatics Protein Synthesis Amino Acid Table Amino Acids
... • When lactose is present it induces the operon by binding to the repressor and changing its shape, causing it to faU off the operator. • When lactose is removed, the repressor goes back to its original sbape and can bind to the operator again. • Because the repressor binds to the operator, the RNA ...
... • When lactose is present it induces the operon by binding to the repressor and changing its shape, causing it to faU off the operator. • When lactose is removed, the repressor goes back to its original sbape and can bind to the operator again. • Because the repressor binds to the operator, the RNA ...
221_exam_3_2003
... ____ The symptoms of viral infection are primarily due to A. the body's response to the invasion B. toxins released by the virus C. insertion of the viral genome into the host cell D. all of the above _____ A repressible operon is important in regulating _____. ...
... ____ The symptoms of viral infection are primarily due to A. the body's response to the invasion B. toxins released by the virus C. insertion of the viral genome into the host cell D. all of the above _____ A repressible operon is important in regulating _____. ...
Chapter 18 Reading Guide
... In case you missed the point, cells use glucose in their cellular metabolism to produce ATP. They do not use lactose (a dissacharide). Therefore, if glucose levels are high, it would be a waste of ATP to produce and enzyme that breaks down dissacharides; however, if glucose levels are low and lactos ...
... In case you missed the point, cells use glucose in their cellular metabolism to produce ATP. They do not use lactose (a dissacharide). Therefore, if glucose levels are high, it would be a waste of ATP to produce and enzyme that breaks down dissacharides; however, if glucose levels are low and lactos ...
Gene Regulation Summary Slide Questions with
... is negative control. 4. How does the Lactose Operon work? What is are the signal proteins, and what do the effect? In what situations is the Lac operon under positive/negative control? The Lac Operon is another example of negative control, where the gene is turned off until there is a signal that it ...
... is negative control. 4. How does the Lactose Operon work? What is are the signal proteins, and what do the effect? In what situations is the Lac operon under positive/negative control? The Lac Operon is another example of negative control, where the gene is turned off until there is a signal that it ...
Document
... • The product of the lacI gene is a repressor, which binds to a unique sequence of DNA bases constituting the operator • When the repressor is bound to the operator, initiation of transcription of lac mRNA by RNA ...
... • The product of the lacI gene is a repressor, which binds to a unique sequence of DNA bases constituting the operator • When the repressor is bound to the operator, initiation of transcription of lac mRNA by RNA ...
Gene Switches - Science Take-Out
... food source. However, if glucose is not available and lactose (a disaccharide) is present in the environment, bacteria can survive by switching on the genes that allow them to use lactose as a food source. The structural genes in the lac operon contain the DNA code that produces three proteins. ...
... food source. However, if glucose is not available and lactose (a disaccharide) is present in the environment, bacteria can survive by switching on the genes that allow them to use lactose as a food source. The structural genes in the lac operon contain the DNA code that produces three proteins. ...
operons operons operons
... • REPRESSABLE OPERONS Usually ON/repressor usually ACTIVE Can be turned off (repressed) Genes for enzymes that make product always needed EX: trp operon makes enzymes used in essential amino acid synthesis ...
... • REPRESSABLE OPERONS Usually ON/repressor usually ACTIVE Can be turned off (repressed) Genes for enzymes that make product always needed EX: trp operon makes enzymes used in essential amino acid synthesis ...
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.