The reactants of enzyme-catalyzed reactions are known as

The correct answer is: substrates

Enzymes are molecule catalysts (usually proteins) with the ability to speed up a chemical reaction by lowering activation energy. Enzymes don’t undergo any permanent chemical change. Reactants of an enzymatic reaction are substrates and they are being changed through the reaction, forming the product of the reaction.

not sure if this is what you'r looking for eubacteria and archaebacteria

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.