Threose has the molecular formula C4H8O4; it is a 4 carbon monosaccharide. Threose has 2 chiral centers and has a aldehyde end, making it an aldose sugar. The two middle carbons are chiral and can orient to D and L stereoisomers. Threose alone has few uses; it is a syrup and very soluble in water. When multiple threose molecules are linked, however, the molecule can be very versatile depending on the linkage. Threose can link with 2 other threose molecules to create threose nucleic acid which can store genetic information. Threose can store nucleotide pairs consisting of A, T, C, G base pairs. Some studies suggest that TNA was a type of genetic material transport before RNA and DNA.
When threose contains an additional hydroxyl group the molecule is an important metabolite of vitamin C. Threose also can be utilized to enhance erthrypoiesis. It is important to note that for the uses of threose, the D-stereoisomer is most commonly used. Not much is known about the function of the L-stereoisomer.