Question

Some target enzymes are activated by addition of a phosphate group (phosphorylation) by a __________, and inactivation is catalyzed by a __________.

Answer 1

Some target enzymes are activated by phosphorylation through the action of kinase enzymes and are inactivated by phosphatase enzymes, which remove the phosphate group.

Step-by-step explanation:

Some target enzymes are activated by the addition of a phosphate group (phosphorylation) by a kinase, and inactivation is catalyzed by a phosphatase.

Phosphorylation is a common post-translational modification that significantly alters the function of proteins, including enzymes. In biochemistry, phosphorylation often regulates enzyme activity by initiating a conformational change in the structure, thereby activating or deactivating the enzyme. This crucial process can be observed in many cellular signaling pathways where a kinase transfers a phosphate from ATP to specific amino acids (serine, threonine, or tyrosine) on the enzyme. Conversely, a phosphatase removes this phosphate group, undoing the phosphorylation and typically reversing the enzyme's activity state.

Answer 2

Enzymes can be activated by the addition of a phosphate group through phosphorylation, which is catalyzed by a kinase, and deactivated by phosphatases removing the phosphate group.

Step-by-step explanation:

Some target enzymes are activated by the addition of a phosphate group (phosphorylation) by a kinase, and inactivation is catalyzed by a phosphatase.

Phosphorylation is a process where a phosphate group is added to molecules like proteins, often to serine, threonine, or tyrosine residues. This chemical modification is essential in cell signaling pathways, affecting enzyme activity or interaction with other molecules in the signaling cascade.

A kinase catalyzes the transfer of a phosphate group from a donor molecule (usually ATP) to an acceptor molecule, such as a protein, typically triggering a functional change in the target molecule, like enzyme activation. Conversely, phosphatases remove these phosphate groups, reversing the modifications and often resulting in the inactivation of the enzyme or other molecule.