What is the proteinaceous part of an enzyme called?

The enzyme involved in the transfer of electrons is ......... .

Name the class of enzyme that usually catalyzes the following reaction:
$S-G + S^* \rightarrow S + S^*-G$
Where,
$G \rightarrow$ a group other than hydrogen
$S \rightarrow$ a substrate
$S^* \rightarrow$ another substrate

From which of the following is the enzyme urease obtained?

What is the enzyme that catalyzes the removal of hydrogen from a substrate in a reaction called?

In the given graph representing enzyme kinetics (Michaelis-Menten kinetics),what does $P$ represent?