This presentation focuses on Organic Chemistry, especially Stereochemistry for 3D shape of molecules. When the same chemical substance differs in its spatial construct it changes in a drastic way its own features, in a biological environment. Ky prezentim fokusohet ne Kimine Organike, ne veçanti ne Stereokimine per formen tredimensionale te molekulave. Kur substanca eshte e njejte por vetem ndryshon konstrukti hapsinor i molekules se saj, ajo ndryshon ne menyre drastike vetite e saj ne mjedise biologjike.