1. PENTOSE PHOSPHATE Pathway Glucose-6-PO 4  Ribose-5-PO 4 Synthesize NADPH for fatty acid synthesis Metabolize pentoses Take Home: The PENTOSE PHOSPHATE pathway is basically used for the synthesis of NADPH and D-ribose. It plays only a minor role (compared to GLYCOLYSIS) in degradation for ATP energy.

2. CHO C-OH HO-C C-OH CH 2 OP COO - C-OH HO-C C-OH CH 2 OP C C-OH HO-C C C-OH CH 2 OP O O NADP + NADPH + H + + H 2 O STAGE I (Oxidation) Glucose-6-PO 4 6-Phosphoglucono-  - lactone 6-Phospho- gluconate G-6-P dehydrogenase Lactonase

3. COO - C-OH HO-C-H C-OH CH 2 OP C=O CH 2 OHC-OH CH 2 OP CHO C-OH CH 2 OP C-OH CO 2 NADP + NADPH + H + Ru5P isomerase Ru5P epimerase Ribose-5-PO 4 STAGE II Xylulose-5-PO 4 Ribulose-5-PO 4 (Ru5P) 6-Phosphogluconate 6-phosphogluconate dehydrogenase CH 2 OH C-OH C CH 2 OP C=O HO-

4. CH 2 OH C-OH C CH 2 OP C=O HO- CHO C-OH CH 2 OP C-OH CH 2 OP C-OH HO-C C=O CH 2 OH + C-OH CH 2 OP CHO Transketolase Sedoheptulose-7-PO 4 Ribose-5-PO 4 Xyulose-5-PO 4 Glyceraldehyde-3-PO 4 STAGE III

5. C-OH CH 2 OP CHO C-OH CH 2 OP C-OH HO-C C=O CH 2 OH C-OH CH 2 OP CHO C-OH CH 2 OP HO-C C=O CH 2 OH + Glyceraldehyde-3-PO 4 Fructose-6-PO 4 Erythrose-4-PO 4 Transaldolase Sedoheptulose-7-PO 4

6. C-OH CH 2 OP CHO CH 2 OH C-OH C CH 2 OP C=O HO- + C-OH CH 2 OP CHO C-OH CH 2 OP HO-C C=OCH 2 OH + Transketolase Erythrose-4-PO 4 Xylulose-5-PO 4 Glyceraldehyde- 3-PO 4 Fructose-6-PO 4

7. SUMMARY 5 + 5  3 + 7 7 + 3  4 + 6 4 + 5  3 + 6 Xylulose-5-PO 4 Ribose-5-PO 4 Glyceraldehyde-3-PO 4 Fructose-6-PO 4 Erythrose-4-PO 4 Sedoheptulose-7-PO 4 TK TA TK

8. 3 Glucose-6-PO 4 + 6 NADP + + 3H 2 O 6 NADPH + 6H+ + 3CO 2 + 2 Fructose-6-PO 4 + Glyceraldehyde-3-PO 4 18 carbons 3 carbons12 carbons 3 carbons 18 = 3 + 12 + 3 Note that: 2. Sedohepulose-7-PO 4, erythrose-4-PO 4 are strictly intermediates 3. Fructose-6-PO 4 is never used as an intermediate 4. Glyceraldehyde-3-PO 4 is both an intermediate and final product 1. For each glucose oxidized, 2 NADPHs are formed

9. The Dangers of Primaquine Hemolytic anemia Glutathione NADPH Reduced hemoglobin and cell lysis G-6-P dehydrogenase Glutathione reductase See p 423 in Textbook Problem