During which process is energy released?

$A$: Many molecules participate in biochemical reactions.
$R$: Biochemical reactions are metabolic reactions.

What types of changes are $P$ and $Q$?
$P -$ Transformation in the shape of a compound without breaking bonds.
$Q -$ Transformation where bonds are broken or new bonds are formed.
$P$ and $Q$ are respectively:

The transformation of metabolites into one another occurs through a series of linked reactions. This is called $...........$.

How do chemical processes occur? Which kinds of changes are observed in them?

When does an organism experience wear and tear?