Pentose phosphate and fates of pyruvate

G6P

Can e inter the pentose phosphate pathway

Pentose phosphate pathway

Generates materials for biosynthesis via NAD

Oxidative phase

Three enzymatic reactions in the oxidative phase convert

glucose 6-phosphate to ribulose 5-phosphate

1. G6P dehydrogenase turns G6P into 6-phosphogluconolactone

2. Lactonase turns that into 6-phosphogluconate

3. Phosphogluconatedehydrogenase turns it into ribulose 5-P

Phosphopentose isomerase

Turns ribulose 5p into ribose 5p

Epimerase

Turns ribulose 5p into xylulose 5p

Transketolase

catalyzes the transfer of a two-carbon

fragment from a ketose donor to an aldose acceptor

• products G3P and sedoheptulose

Transaldolase

catalyzes the transfer of three

carbons to make fructose 6-phosphate

Transketolase 2

catalyzes a second reaction to form

fructose 6-phosphate and glyceraldehyde 3-phosphate l