Which enzyme is responsible for the hydrolysis of lactose?

Which of the following is an example of competitive inhibition of enzymes,where succinate is the substrate?

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

"Enzymes are proteins", it was suggested by

Which of the following is not an attribute of enzymes?

An enzyme can be synthesised by chemically bonding together molecules of