(1) An aldopentose (which means a five carbon sugar with an aldehyde functional group in its linear form) with a chemical formula C5H10O5
(2) A sugar monomer in RNA (Ribonucleic acid); also found in other metabolically important compounds, e.g. ribonucleotides, nucleic acids, riboflavin, etc.
Its close relative is deoxyribose, which is a constituent of dna (deoxyribonucleic acid). The difference between them is that ribose has one more oxygen atom in its molecule than deoxyribose.
Word origin: German, alteration of English arabinuse, a kind of sugar
Chemical formula: C5H10O5