Decision making is one of the distinguishing properties of biosystems. Decision making of course does not necessarily mean conscious decision making, which is exclusively human. On the contrary, the ability to make decisions can be observed in every living organism even in unicellular species as a type of molecular logic, in the form of chemotaxis). Chemotaxis is chemistry-driven motility: towards areas of increasing concentrations of friendly chemicals (positive chemotaxis) and away from increasing concentrations of hostile chemicals (negative chmotaxis).
Although the principle of chemotaxis is purely chemical, it would be incorrect to say that all aspects of biological life are reducable to chemistry and physics. Even chemotaxis itself occurs in a living cell in the context of other systems, notably with the metabolic system, which are all interconnected in a single controlled and functioning whole.
Molecular logic is used in nanoelectronics. Here, clearly, there are distinct rules for signal processing that are loaded on top of constraints (i.e. chemical interactions).