Protein kinases are enzymes that act on other enzymes by adding phosphates groups. When the enzyme is phosphorylated, it changes its activity (it becomes more or less active, depending on the enzyme). This regulatory mechanism of enzymatic activity is called

The feedback inhibition regulatory mechanism. They do this by causing phosphorylation of the other enzyme.

Explanation:

There are two ways by which enzymes can be controlled or regulated. This includes

1. Controlling the synthesis of the enzyme (this relates to a genetic control)

2. Controlling the activity of the enzyme (feedback inhibition).

In this example here, the protein kinases act on other enzymes by adding phosphates groups bringing about phosphorylation and controlling or regulating the activity of these enzymes. Thus, this type of regularly is the feedback inhibition regulatory mechanism.

the wires in the toaster turning red and the toast crisping and turning brown

the electromagnetic energy from the sun arrives in the form of visible and invisible light.