Exam 7: Metabolic Regulation

Cyclic AMP (cAMP)is involved in the global regulation of catabolic pathways in Escherichia coli,including the lac operon,and a low activity of adenylate cyclase that makes cAMP is suggestive of catabolite repression.

The function of a kinase is

Defend why is it unsurprising that two-component regulatory systems are all but absent in bacteria that live at the expense of a host?

Proteins required at approximately the same level throughout a cell's growth cycle are often not subject to regulatory mechanisms and are constitutively synthesized.

During chemotaxis,attractants increase the rate of autophosphorylation whereas repellants decrease this rate.

A two-component regulatory system usually involves both the sensor and response proteins being subject to phosphorylation.

How could you identify potential riboswitches with bioinformatics tools?

Explain the function of cAMP in catabolite repression.

The lac operon is an example of ________ control in which the presence of an ________ is required for transcription to occur.

Some proteins that bind to DNA block transcription,whereas other proteins can activate transcription.

Interpret the results to the following experiment.Transcriptional activity of chemotactic genes showed a high expression level during the following conditions: repelling away from compound 1,moving towards compound 2,and remaining sessile when presented compounds 3 and 4.

Describe the basic two-component regulatory system,and compare the function of each component.

Quorum sensing generally follows the mechanism of which type of regulation?

Small molecules usually act directly (rather than indirectly)in regulating transcription.

In most cases,the first product of a particular biosynthetic pathway represses the enzymes of the pathway.

Regulation of an enzyme's activity occurs

In catabolic repression,cells use the least abundant carbon source first.

The most frequent way in which regulatory RNA molecules exert their effects is by

Proteins and RNA molecules that are needed in the cell,at about the same level under all growth conditions,require constitutive expression.

When arginine is added to a culture growing exponentially in a medium without arginine,what occurs?