3d image of erythrose skeletal formula

erythrose tetrose saccharide aldose trihydroxybutanal diastereomer intermediate pentose phosphate pathway calvin cycle sole energy source aldotetrose metabolite metabolism biosynthesis mechanism path catabolism biosynthetic intermediate biogenesis substrate precursor synthesis derivative bioprecursor metabolic enzyme endogenous contractor molecule molecular formula skeletal structural structure cell biochemistry biomolecule bioactive biochemical chemistry science scientific research organic chemical 3d