The spelling of the word "RUBPCO" can be broken down using the International Phonetic Alphabet (IPA) transcription. Beginning with the letter "R," it is pronounced as /ɑr/, followed by the letter "U," pronounced as /ju/. The next three letters, "BPC," are pronounced as individual letters: "B" /bi/, "P" /pi/, and "C" /si/. Finally, the last letter "O" is pronounced as /oʊ/. When spoken altogether, the word "RUBPCO" sounds like /ɑr ju bi pi si oʊ/.