Xylulose-5-phosphate is an intermediate in the pentose phosphate pathway (see Figure 12.36). As xylulose-5-phosphate levels rise in response to excess glucose shunting through the pentose phosphate pathway, does flux through glycolysis increase or decrease?

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CEP G6P CXIDATIVE PHASE NADP 2 NADP NADH CO2 SPa 6PG Ru5 P (NADP NAD F6P GAP co RuSP RusP FBP Głycolysis NONOXIDATIVE PHASE RS P aAP 2 ATP Nucleotides 002 a) Nucleotide ayntheaia When the primary need is ior nuclaotide biosynmhesis,1he primary produci is ribose--phosphata. DHAPFBP Chric cycle b)NADPHayntheeia. When the primary need is or reducing pover (NADPH), ruclose phcsphates sle reconverded 1o glucose-e-phos phete tor ecxidation in thecidslive phese FADH NADH ABBREVIATIONS GeP -glucose-e-phosphata R5P-ritose-s-phosphate (b) Energy generatian. F6P-ucose-e-phosphate DHAP dihydroxyacelone phosphate FBP-ructse-1e-bisphosphsle Whanonly moderate quanties pentose ρ hosphales and NA DP H are needed. 1 he pathveycan also be usad to supply energy withthe resclion producis being oxidized thiro ugh ghycolysi snd1he ciric acidcycla