What is the function of the pentose phosphate pathway’s oxidative phase?

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Multiple Choice

What is the function of the pentose phosphate pathway’s oxidative phase?

The oxidative phase of the pentose phosphate pathway creates reducing power and a sugar phosphate for biosynthesis. In this phase, glucose-6-phosphate is oxidized twice, with NADP+ reduced to NADPH both times. The first oxidation forms NADPH and a lactone; the lactone is hydrolyzed to 6-phosphogluconate, which is then decarboxylated to ribulose-5-phosphate while generating a second NADPH and releasing CO2. This sequence provides two NADPH molecules per glucose-6-phosphate, plus ribulose-5-phosphate (which can be isomerized to ribose-5-phosphate for nucleotide synthesis). These steps do not produce ATP or FADH2, and lactate is not a product of this pathway.

The oxidative phase of the pentose phosphate pathway creates reducing power and a sugar phosphate for biosynthesis. In this phase, glucose-6-phosphate is oxidized twice, with NADP+ reduced to NADPH both times. The first oxidation forms NADPH and a lactone; the lactone is hydrolyzed to 6-phosphogluconate, which is then decarboxylated to ribulose-5-phosphate while generating a second NADPH and releasing CO2. This sequence provides two NADPH molecules per glucose-6-phosphate, plus ribulose-5-phosphate (which can be isomerized to ribose-5-phosphate for nucleotide synthesis). These steps do not produce ATP or FADH2, and lactate is not a product of this pathway.

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