Scheme is a type of Concept. Possibility is a type of Concept. Possible is a type of Possibility. Possible is related to Would. 
Sugar is a type of Molecule. you are likely to find Molecule in/at/on Hand. Hand is related to Apple. 
Scheme --IsA--> Concept <--IsA-- Possibility <--IsA-- Possible <--RelatedTo--> Would 
Sugar --IsA--> Molecule --AtLocation--> Hand <--RelatedTo--> Apple 