In the graph to the right it shows the activation energy needed in a reaction. assuming that both lines a and b are of the same reaction which line likely had an enzyme present? how do you know?

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.