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What happens when the cell is not in the presence of tryptophan?
Wiki User
∙ 10y ago
RNA polymerase can transcribe mRNA
Wiki User
∙ 10y ago
When the cell is not in the presence of tryptophan, it activates a regulatory protein called the trp repressor. This repressor binds to the DNA in the promoter region of the operon controlling tryptophan synthesis, preventing RNA polymerase from transcribing the genes. As a result, the production of enzymes involved in tryptophan synthesis is inhibited.
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The expression of the tryptophan operon is controlled by?
The expression of the tryptophan operon is controlled by a repressor protein that binds to the operator region in the presence of tryptophan. When tryptophan levels are high, the repressor is active and prevents transcription of the operon. When tryptophan levels are low, the repressor is inactive, allowing transcription to occur.
How is the trp repressor protein and allosteric protein?
If Tryptophan is low in the diet, the repressor changes shape and allows the RNA polymerase to attach and copy the DNA so that Tryptophan can be produced by the cell.
What chemical grouping is responsible for a positive Hopkins-Cole test?
Tryptophan
What vitamin can be made from the amino acid tryptophan?
Vitamin B3, also known as niacin, can be synthesized in the body from the essential amino acid tryptophan. Tryptophan is converted into niacin through several metabolic pathways.
Is trytophan an acid or a base?
Like any other amino acid, tryptophan possesses both acidic and basic characteristics, referred to as amphoteric substances. It acts as an acid at pH below 5.89 and as a base at pH above 5.89. 5.89 here is the isoelectric point of tryptophan, a pH value where its overall charge is zero and wherein it neither acts as an acid, nor as a base.
Why is the tryptophan operon turned off in the presence of tryptophan?
The tryptophan operon is turned off in the presence of tryptophan because tryptophan acts as a corepressor. When tryptophan levels are high, it binds to the trp repressor protein. This trp-repressor complex then binds to the operator region of the operon, preventing RNA polymerase from transcribing the genes involved in tryptophan synthesis.
The expression of the tryptophan operon is controlled by?
The expression of the tryptophan operon is controlled by a repressor protein that binds to the operator region in the presence of tryptophan. When tryptophan levels are high, the repressor is active and prevents transcription of the operon. When tryptophan levels are low, the repressor is inactive, allowing transcription to occur.
What would happen if the amount of tryptophan being produced in an E.coli cell when the repressor is attached to the operator?
If the repressor is attached to the operator, it will prevent RNA polymerase from transcribing the genes responsible for tryptophan production. As a result, the production of tryptophan in the E. coli cell will be inhibited, leading to a decrease in the levels of tryptophan synthesized.
What is Hopkins's test?
The hopkins-cole test is used to determine the presence of the amino acid tryptophan. Tryptophan has an indole nucleus which is responsible for the violet ring found at the junction between the two layers.
What is the Hopkins Cole test?
The hopkins-cole test is used to determine the presence of the amino acid tryptophan. Tryptophan has an indole nucleus which is responsible for the violet ring found at the junction between the two layers.
What is the substrate for the Indole test?
The substrate for the Indole test is tryptophan, which is converted by the enzyme tryptophanase into indole, pyruvic acid, and ammonia. The presence of indole can be detected by the addition of Kovac's reagent, which forms a red color in the presence of indole.
Is fungi the presence or absence of a cell?
fungi is the presence of a cell
How is the trp repressor protein and allosteric protein?
If Tryptophan is low in the diet, the repressor changes shape and allows the RNA polymerase to attach and copy the DNA so that Tryptophan can be produced by the cell.
Why should excess bromine water be avoided in the test for free tryptophan?
Excess bromine water should be avoided in the test for free tryptophan because it can cause the breakdown of tryptophan, leading to false negative results. Bromine water is a strong oxidizing agent that can react with tryptophan and other organic compounds, potentially altering the test outcome.
How is lac operon different from trp operon?
1. in lac operon; gene activity is induced when lactose is present in the medium, whereas in case of trp operon, repression of the gene activity takes place in presence of tryptophan in the medium. 2. lac operon spans about 4-6kb...whereas trp operon spans abut 7kb. 3. lac operon helps in the breakdown of lactose into glucose and galactose, to generate energy( catabolic pathway ) in case of trp operon, it helps in the synthesis of enzymes required for the formation of the amino acid Tryptophan( anabolic pathway ). 4. lac operon is an example of positive regulation ; and trp operon is an example of negative regulation. Trp operon is also regulated by other mechanism called attenuation while no such even occurs in lac operon . .
What is the chemical formula for tryptophan?
The chemical formula for tryptophan is C11H12N2O2
What do the upper chloroform layer develops in salkowski test?
In the Salkowski test, the upper chloroform layer develops a yellow color due to the reaction between tryptophan and sulfuric acid. This color change indicates the presence of indole compounds, which are produced by some bacteria during tryptophan metabolism.
