However, this pathway does oxidize glucose and under certain conditions can completely oxidize glucose to CO 2 and water. As a consequence, cells of the liver , adipose tissue , adrenal cortex , testis and lactating mammary gland have high levels of the PPP enzymes. The reactions of oxidative portion of the pentose phosphate pathway are shown. The enzymes are in green. The reactions of the non-oxidative portion of the pentose phosphate pathway are shown.
Enzymes are in green.
Relevant carbohydrate intermediates of this portion of the pathway are in red. The reactions of the PPP operate exclusively in the cytoplasm. The pentose phosphate pathway has both an oxidative and a non-oxidative arm. The primary enzymes involved in the non-oxidative steps of the PPP are transaldolase and transketolase . The transaldolase reaction involves Schiff base formation between the substrate and a lysine residue in the enzyme.