[PeterisP]

DNA and proteins are obviously discrete, so even if the hardware relies on some fundamental analogous behavior, the 'software' and each hardware component can still be analyzed as discrete behavior.

However, for anything operating at human temperatures we can reasonably assume that any effective behavior can be simulated by discrete operations, as any nuances of fundamental analogousness would be drowned by thermal noise and the amount of precision that any behavior can require is rather low, much lower than e.g. any standard floating point number in a discrete CPU.