Sigh. Just because you don’t know ketones are the building block of key aminos, doesn’t mean you should say “they are a completely different group of chemicals”.
That’s like saying two slices of bread and a spoonful of peanut butter is a completely different thing than a peanut butter sandwich.
Umm, a ketone is defined by the chemical group C=O with R groups (usually a carbon atom or chain) branching off of the carbon.
Doesn’t HAVE to be an amino acid when all is said and done.
It’s like the “all cats are mammals” and all that.