We explore the computational power of biochemistry with respect to basic chemistry, identifying complexation as the basic mechanism that distinguishes the former from the latter. We use two process algebras, the Chemical Ground Form (CGF) which is equivalent to basic chemistry, and the Biochemical Ground Form (BGF) which is a minimalistic extension of CGF with primitives for complexation. We characterize an expressiveness gap: CGF is not Turing complete while BGF supports a finite precise encoding of Random Access Machines, a well-known Turing powerful formalism.