re: body constituents
I think Sagan's book, "Cosmos" had a section about this. I remember on the
video version where he was standing next to a large plexiglass container
with a pile of materials in the middle...carbon, sulfer, iron, etc. and was
talking about how "just adding water" would still fall short of making a
human. Sounds silly now but you might find what you want in his book.