Good point about protein folding. Right now it's simulated with classical physics on conventional computers; quantum chemistry algorithms on classical computers scale too poorly for use with macromolecules. But a many-qubit computer could be excellent for that and other molecular-scale calculations. (Not that getting good protein folding models would cure cancer, but it's reasonably likely to aid biological research.)

Ab-initio quantum chemistry calculations certainly could scale much better on quantum computers -- I skimmed a paper once, which made it sound not easy but definitely worth working on -- and that's bound to help with bioscience once they're big enough. I'm surprised at protein folding or fluid dynamics, though -- what's the general idea on how it'd help with those?

Added: that is, I thought protein conformation energy was pretty well approximated with classical molecular-mechanics models, except during actual chemical reactions, and the difficulty was the sheer amount of time it takes this huge molecule to settle down to an energy minimum that's only a little below that of many alternative conformations. Is the biggest problem rather that we can't efficiently compute a consistent-enough approximation to the energy of a given conformation, so we can't distinguish the best conformation of the ones we simulated?

Based on what I read after I saw the protein folding suggestion, the idea is that with a Sufficiently Advanced quantum computer, you could use fully quantum calculations for small molecules and proteins alike. I'm puzzled about fluid dynamics too, though.

All current fluid simulations are iterative and assume the fluid is a continuous indivisible mass (e.g. that it is not composed of atoms or molecules) that we then turn into discrete regions to compute the simulations. Even without common simplifying assumptions (to gain performance), this still has limits. Theoretically, simulating the regions with a quantum computer would allows us to remove these limits, and get the performance without making simplifying assumptions.

That sounds super-ambitious, but if humans can make LIGO, there must be a lot we can do.