Sugar phosphates

The phosphodiester backbone of DNA and RNA consists of pairs of deoxyribose or ribose sugars linked by phosphates at the respective 3' and 5' positions.

Not only ribose 5-phosphate but also fructose 6-phosphate are an intermediate of the pentose-phosphate pathway which generates nicotinamide adenine dinucleotide phosphate (NADPH) and pentoses from glucose polymers and their degradation products.)

PNA cannot be degraded inside living cells but it is chemically stable and resistant to hydrolytic (enzymatic) cleavage.

Not only ribose 5-phosphate but also fructose 6-phosphate are an intermediate of the pentose-phosphate pathway which generates nicotinamide adenine dinucleotide phosphate (NADPH) and pentoses from glucose polymers and their degradation products.

This ability is shared by certain other metabolites (e.g. glucose 1-phosphate) from which the accepted Calvin-cycle intermediates could easily be derived by known metabolic routes.