Covalent Regulation of Glutamine Synthetase

The video explains the covalent regulation of glutamine synthetase, an enzyme that converts glutamate to glutamine. It details how the enzyme is regulated by adenylation and deadenylation, involving adenyl transferase and uridyl transferase. The regulation is influenced by cellular energy states, with high ATP and alpha-ketoglutarate levels promoting biosynthesis, while low energy states favor catabolism. The video also introduces the role of P2 protein in this regulatory mechanism.

What is the primary function of glutamine synthetase?

• To convert glutamine to glutamate

• To convert glutamate to glutamine

• To degrade ammonia

• To synthesize ATP

How is glutamine synthetase inactivated?

• By phosphorylation

• By adenylylation

• By acetylation

• By methylation

What role does uridyl transferase play in the regulation of glutamine synthetase?

• It adds a UMP group to P2 protein

• It degrades glutamine synthetase

• It removes an AMP group from glutamine synthetase

• It adds a phosphate group to glutamine synthetase

Which molecules stimulate uridyl transferase activity?

• High levels of glutamine and phosphate

• High levels of ATP and alpha-ketoglutarate

• Low levels of ATP and alpha-ketoglutarate

• High levels of ammonia

What happens to glutamine synthetase when the cell is in a low energy state?

• It becomes more active

• It synthesizes more ATP

• It converts glutamine to glutamate

• It is inactivated

What is the effect of high energy charge on glutamine synthetase activity?

• It activates glutamine synthetase for biosynthesis

• It has no effect on glutamine synthetase

• It promotes the conversion of glutamine to glutamate

• It leads to the inactivation of glutamine synthetase

Which enzyme indirectly regulates glutamine synthetase through allosteric effectors?

• Glutamate dehydrogenase

• Phosphorylase

• Uridyl transferase

• Adenylyl transferase