We develop a minimal model for an enzyme that allows us to extract a set of golden rules regarding its optimal design. We discover that two key ingredients of momentum conservation and a generically present dissipative coupling give rise to a bifurcation in the dynamical phase portrait of the low-dimensional configuration space, which enables enzymatic activity as an emergent feature of the dynamics, via a fundamentally novel mechanism not accessible to Kramers-like energy-barrier-crossing descriptions in terms of reaction coordinates.