I kinda agree with both of you if it's possible...
Given enough time we'll achieve an understanding of ourselves and our "functions" like the ones cited by diablokgb such as love hate etc and then like Neptunus said we can build an AI inspired by that knowledge with biomolecules and inorganic compounds, why not?.
It's not even close to it, but John craig venter made something like he wrote a genome with all and only the necessary genes to a bacterium to live on independently that he transfected to a bacterium (which was emptied of all genomic information before) (I put the link below for those who might want to look this up or do further researchs)
And a cell is supposed to be way easier to understand than a multicellular being.
So to come back to the topic, I think that since we can't make an artificial cell, by the time we can gather all the knowledge to make a real AI as we can see in the most futuristic movies we'll all (and I mean humanity, not just you and me) be dead already or something
But we already have some AI, and in 50 years we'll have improved that, but it won't be as "perfect" as we are, so like diablokgb I think it's impossible but time being the problem, not that it's just too hard.
https://en.m.wikipedia.org/wiki/Mycoplasma_laboratoriumWhat Neptune was referring to as in biomolecules was....us, humans....