Hormone is a type of Molecule. Iron is part of Molecule. Steel is made of Iron. you are likely to find Steel in/at/on Mill. 
Fish is related to Place. Beach is a type of Place. 
Hormone --IsA--> Molecule <--PartOf-- Iron <--MadeOf-- Steel --AtLocation--> Mill 
Fish <--RelatedTo--> Place <--IsA-- Beach 