document
... walk into an ice-cream bar. The two youngsters order delicious 100% whole milk milkshakes, while their parents look on enviously and order non-dairy fruit smoothies. Why do you think the parents didn’t order milkshakes? ...
... walk into an ice-cream bar. The two youngsters order delicious 100% whole milk milkshakes, while their parents look on enviously and order non-dairy fruit smoothies. Why do you think the parents didn’t order milkshakes? ...
Exam 3
... genomes. Understand that a bacterial cell with a virus engaged in the lytic cycle will soon die. What is the lysogenic cycle, and specifically what is the prophage? Understand that not all bacteriophage are able to perform a lysogenic cycle, but all bacteriophage can perform a lytic cycle. Understan ...
... genomes. Understand that a bacterial cell with a virus engaged in the lytic cycle will soon die. What is the lysogenic cycle, and specifically what is the prophage? Understand that not all bacteriophage are able to perform a lysogenic cycle, but all bacteriophage can perform a lytic cycle. Understan ...
zChap12_140901 - Online Open Genetics
... carry one copy, while the other is on the genomic E. coli chromosome. This results in a partial diploid in E. coli. The F-factor is an episome that is capable of being either a free plasmid or integrated into the host bacterial chromosome. This switching is accomplished by IS elements where unequal ...
... carry one copy, while the other is on the genomic E. coli chromosome. This results in a partial diploid in E. coli. The F-factor is an episome that is capable of being either a free plasmid or integrated into the host bacterial chromosome. This switching is accomplished by IS elements where unequal ...
Analysis of the LacI family of repressor proteins in non
... It is a cogent depiction of how a set of 'structural' genes may be coordinately transcribed in response to environmental conditions and regulates metabolic events in the cell (Lewis, 2005). Binding of the lacO operator region by the LacI repressor protein in E. coli is well studied. Blast analysis o ...
... It is a cogent depiction of how a set of 'structural' genes may be coordinately transcribed in response to environmental conditions and regulates metabolic events in the cell (Lewis, 2005). Binding of the lacO operator region by the LacI repressor protein in E. coli is well studied. Blast analysis o ...
Differential Gene Expression
... • The lac operon is an inducible operon and contains genes that code for enzymes used in the hydrolysis and metabolism of lactose • By itself, the lac repressor is active and switches the lac operon off • A molecule called an inducer inactivates the repressor to turn the lac operon on ...
... • The lac operon is an inducible operon and contains genes that code for enzymes used in the hydrolysis and metabolism of lactose • By itself, the lac repressor is active and switches the lac operon off • A molecule called an inducer inactivates the repressor to turn the lac operon on ...
Bacterial Regulation
... A particular enzyme appears in the cell only after the cell has been exposed to the enzyme’s substrate This observation became known as enzyme adaptation ...
... A particular enzyme appears in the cell only after the cell has been exposed to the enzyme’s substrate This observation became known as enzyme adaptation ...
Modeling Biological Pathways: an Object-oriented like
... typical example of this behavior since it can alter the enzymes concentrations to take full advantage for sugars fluctuation in its environment. So a bacterium avoids synthesizing the enzymes of a pathway in absence of the substrates, but it is ready to produce the enzymes if the substrate should ap ...
... typical example of this behavior since it can alter the enzymes concentrations to take full advantage for sugars fluctuation in its environment. So a bacterium avoids synthesizing the enzymes of a pathway in absence of the substrates, but it is ready to produce the enzymes if the substrate should ap ...
Structures in the lac
... 5) LacZ: broken, doesn't produce the B-galactosidase to convert lactose into glucose and galactose (NOTE: If this Level 2 is too similar to Level 3, it could be a broken part such as the RNA polymerase, repressor, B-galactosidase, and/or B-galactoside permease) Answer Dialog box: Good job! You have ...
... 5) LacZ: broken, doesn't produce the B-galactosidase to convert lactose into glucose and galactose (NOTE: If this Level 2 is too similar to Level 3, it could be a broken part such as the RNA polymerase, repressor, B-galactosidase, and/or B-galactoside permease) Answer Dialog box: Good job! You have ...
ACT - Operon -S - saddlespace.org
... smaller molecules in the environment? Justify your answer with specific details from Model 1 or Model 2. ...
... smaller molecules in the environment? Justify your answer with specific details from Model 1 or Model 2. ...
Control of Gene Expression in Prokaryotes
... environmental factors. Sometimes related genes are grouped together with one switch. This group of genes, along with the sections of DNA that regulate them, is called an operon. ...
... environmental factors. Sometimes related genes are grouped together with one switch. This group of genes, along with the sections of DNA that regulate them, is called an operon. ...
Chapter 12
... • Each inverted repeat of the operator binds to the DNA-binding site of one repressor subunit. • Inducer binding causes a change in repressor conformation that: – reduces its affinity for DNA – releases it from the operator ...
... • Each inverted repeat of the operator binds to the DNA-binding site of one repressor subunit. • Inducer binding causes a change in repressor conformation that: – reduces its affinity for DNA – releases it from the operator ...
Lecture 1
... An overview of the mechanisms that can be used in regulation.The product of gene A is an enzyme A, which in this case is synthesised constitutively and carries out its reaction. Enzyme B is also synthesised constitutively but its activity can be inhibited. The synthesis of the product of gene C can ...
... An overview of the mechanisms that can be used in regulation.The product of gene A is an enzyme A, which in this case is synthesised constitutively and carries out its reaction. Enzyme B is also synthesised constitutively but its activity can be inhibited. The synthesis of the product of gene C can ...
Lec 10 - Regulation of Gene
... The production or synthesis of a particular enzyme is not constant. It varies as per the requirement of the cell in other words, the synthesis of a particular enzyme is sometimes high and sometimes low depending upon the requirement of the cell. Thus, there exists an on-off system which regulates pr ...
... The production or synthesis of a particular enzyme is not constant. It varies as per the requirement of the cell in other words, the synthesis of a particular enzyme is sometimes high and sometimes low depending upon the requirement of the cell. Thus, there exists an on-off system which regulates pr ...
Regulation of Gene Expression
... Each of your cells has at least 20,000 genes. In fact, all of your cells have the same genes. Do all of your cells make the same proteins? Obviously not. If they did, then all your cells would be alike. Instead, you have cells with different structures and functions. This is because different cells ...
... Each of your cells has at least 20,000 genes. In fact, all of your cells have the same genes. Do all of your cells make the same proteins? Obviously not. If they did, then all your cells would be alike. Instead, you have cells with different structures and functions. This is because different cells ...
Bacterial Gene Regulation
... • Glucose is the preferred energy source • metabolized via glycolysis • a monosaccharide • Lactose is an alternative, only metabolized if needed • A disaccharide • Thus, the lac operon is inducible, turned on when needed but off the rest of the time ...
... • Glucose is the preferred energy source • metabolized via glycolysis • a monosaccharide • Lactose is an alternative, only metabolized if needed • A disaccharide • Thus, the lac operon is inducible, turned on when needed but off the rest of the time ...
Lysines 72, 80 and 213 and aspartic acid 210 of the
... Fig. 2. Multiple sequence alignment between the members of the E.coli DeoR family of repressors. LacR Smu, LacR Sau, GutR Eco, FucR Eco, DeoR Eco and AccR Atu are proteins involved in the regulation of the S.mutans and S.aureus lactose operons (Oskouian and Stewart, 1990; Rosey and Stewart, 1992), E ...
... Fig. 2. Multiple sequence alignment between the members of the E.coli DeoR family of repressors. LacR Smu, LacR Sau, GutR Eco, FucR Eco, DeoR Eco and AccR Atu are proteins involved in the regulation of the S.mutans and S.aureus lactose operons (Oskouian and Stewart, 1990; Rosey and Stewart, 1992), E ...
Exam 1 Q2 Review Sheet
... 2. Describe the history concerning the discovery of the structure of DNA. Be sure to include the findings of Miescher, Levene, Chargaff, Franklin, Watson and Crick. 3. Know the structure of DNA and how to draw the various nucleotides. 4. Explain how DNA is replicated using diagrams and descriptions. ...
... 2. Describe the history concerning the discovery of the structure of DNA. Be sure to include the findings of Miescher, Levene, Chargaff, Franklin, Watson and Crick. 3. Know the structure of DNA and how to draw the various nucleotides. 4. Explain how DNA is replicated using diagrams and descriptions. ...
Gene Expression in Prokaryotes
... operon. Then the trpE-A genes are translated, and the biosynthesis of tryptophan occurs Domain 4 is called the attenuator because its presence is required to reduce (attenuate) mRNA transcription in the presence of high levels of tryptophan. ...
... operon. Then the trpE-A genes are translated, and the biosynthesis of tryptophan occurs Domain 4 is called the attenuator because its presence is required to reduce (attenuate) mRNA transcription in the presence of high levels of tryptophan. ...
Regulation of Gene Expression
... The trp and lac operons discussed above are examples of negative control because a repressor blocks transcription. In one case (lac operon) the repressor is active and prevents transcription. In the other case (trp) the repressor is inactive and must be activated to prevent transcription. Positive c ...
... The trp and lac operons discussed above are examples of negative control because a repressor blocks transcription. In one case (lac operon) the repressor is active and prevents transcription. In the other case (trp) the repressor is inactive and must be activated to prevent transcription. Positive c ...
Biology 6 Study Guide – Exam #2
... This is a list of general topics you should be prepared to answer questions on for each chapter. This guide is NOT what you should study but rather is a guide to help organize your studying of the material listed. Your actual studying should involve the textbook, Powerpoint slides, your notes and ot ...
... This is a list of general topics you should be prepared to answer questions on for each chapter. This guide is NOT what you should study but rather is a guide to help organize your studying of the material listed. Your actual studying should involve the textbook, Powerpoint slides, your notes and ot ...
A document that can help for writing your lab report: www
... If X-gal and IPTG are contained within an agar medium on a culture plate, you can easily distinguish which colonies have a functional LacZ gene. IPTG (Isopropyl-β-D-thio-galactoside) is frequently used as an inducer of the lac operon for physiological work. It binds to repressor and inactivates it ...
... If X-gal and IPTG are contained within an agar medium on a culture plate, you can easily distinguish which colonies have a functional LacZ gene. IPTG (Isopropyl-β-D-thio-galactoside) is frequently used as an inducer of the lac operon for physiological work. It binds to repressor and inactivates it ...
Chapt 11
... DNA packing can prevent gene expression by preventing RNA polymerase and other transcription proteins from contacting the DNA. Cells seem to use higher levels of packing for long-term inactivation of genes. Highly compacted chromatin, found in varying regions of interphase chromosomes, is gen ...
... DNA packing can prevent gene expression by preventing RNA polymerase and other transcription proteins from contacting the DNA. Cells seem to use higher levels of packing for long-term inactivation of genes. Highly compacted chromatin, found in varying regions of interphase chromosomes, is gen ...
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.