Mostly I have a hard time accepting that a Turing machine can experience "consciousness"/awareness. Therefore I also have a hard time with simulatable chemical processes; it feels like there is some missing link there.

All just feelings/vibes unfortunately.

I can sympathise with you, but how could a "quantum" effect" doesn't make this easier?

Maybe "Turing machine" is too abstract or simplistic as a concept? Both for real computers and brains?

I can see that a computer is on some level just a lot of sand (silica and metal) but put together in a really complex way, it "suddenly" can add and compare numbers … if we observe the complexity levels from sand to computer and try to see the analogy when comparing cells / neurons to a structure of billions of them somehow interconnected on both a physical and chemical level, evolved during millions of years, I have no problem to accept that brains are still too complex to explain for us.