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2021-05-14

Which term most appropriately refers to a regulatory protein in prokaryotes?

Which term most appropriately refers to a regulatory protein in prokaryotes?

Positive control. Which term most appropriately refers to a regulatory protein in prokaryotes? DNA binding protein.

Which term refers to a series of related genes that are under coordinated control?

repressor; constitutively expressed. What its the significance of germ cell mutations? they are usually found in every cell of the next generation. Which term refers to a series of related genes that are under coordinated control? operon.

At what level is genetic regulation most likely in prokaryotes?

transcriptional level

What would be the effect of a mutation in the lacI gene that prevented the repressor from binding to lactose?

Lactose is an inducer of the lac operon. What would be the effect of a mutation in the lacI gene that prevented the repressor from binding to lactose? Glucose decreases the levels of cAMP in the cell, preventing formation of the CAP-cAMP complexes necessary for the stimulation of transcription from the lac operon.

How many types of lac operon are there?

Three of the enzymes for lactose metabolism are grouped in the lac operon: lacZ, lacY, and lacA (Figure 12.1. 1). LacZ encodes an enzyme called β-galactosidase, which digests lactose into its two constituent sugars: glucose and galactose.

Why is attenuation not found in eukaryotes?

1). There is no coupling of transcription and translation in eukaryotic cells as in bacterial cells. Consequently, ribosome movement and arrest cannot modulate attenuation.

What are the key differences between the LAC and Trp operons?

The lac operon responds to an inducer that causes the repressor to dissociate from the operator, derepressing the operon. The trp operon responds to a repressor protein that binds to two molecules of tryptophan. When the tryptophan is plentiful, this repressor-tryptophan complex binds to the trp operator.

What happens when tryptophan levels are high?

When levels of tryptophan are high, attenuation causes RNA polymerase to stop prematurely when it’s transcribing the trp operon. Only a short, stubby mRNA is made, one that does not encode any tryptophan biosynthesis enzymes.

Is lac operon catabolic or anabolic?

catabolic operons such as lac (which produces the enzymes that digest lactose) are induced to be transcribed when a substance to be catabolized enters the cell. anabolic operons such as trp (which produces the enzymes that manufacture tryptophan) are repressed when the cell is saturated with the product of the operon.

What is positive regulation of lac operon?

The association between RNA polymerase and DNA is enhanced when the CAP-cAMP complex is present. Enhanced RNA polymerase binding leads to a high rate of transcription and translation of the lac operon structural genes lacZ, lacY, and lacA. The protein products of lacZ, lacY, and lacA metabolize lactose into glucose.

Which type of operon would be used for anabolic reactions?

Repressible operons

Is Lactose a Corepressor in the lac operon?

The lac operon is dubbed inducible because it is off by default, but switched on when lactose-the inducer-is present. It is also said to be negatively controlled, because a repressor protein is bound to the operon by default, shutting it off. So, tryptophan acts as a corepressor for its own operon.

Can you think how long the lac operon would be expressed in the presence of lactose?

The Lactose operon expresses as long as the Lactose is present. When all lactose is converted into glucose and galactose, the reaction stops.

Can you think for how long the lac operon?

Answer Expert Verified The Lactose operon expresses as long as the Lactose is present. When all lactose is converted into glucose and galactose, the reaction stops….

How does glucose affect the lac operon?

The lac operon has an added level of control so that the operon remains inactive in the presence of glucose even if lactose also is present. High concentrations of glucose catabolites produce low concentrations of cAMP, which must form a complex with CAP to permit the induction of the lac operon.