Ebiramu byonna bikolebwa mu molekyu z’ebiramu(organic molecules) ; ebiramu byonna birimu asidi wa nyukiraiki(nucleic acids) ne asidi za amina(amino acids) ezikola kazimbamubiri(proteins). Asidi za nyukiraiki ne kazimbamubiri mu buttonde ziri mu biramu byokka. Ensengekera z’ ebiramu zonna era zirina okufaanana kwa molekyu, ekiraga nti birina obujajja bwe bumu olw’okuba nti kirabika byakolebwa okuva mu busirigini(genes) bwe bumu.