Biochemistry

During these transformations, 2 NADP molecules are reduced to NADPH 2 , which can be used for various reduction syntheses. Ribuloso-5-phosphate under the influence of an isomerase easily turns into a biologically important sugar - ribose-5-phosphate. A state of labile equilibrium is established between both forms of pentose phosphates: A H HCOH HCOH . Н(!он I CHtOPOgHj Ribose-5-phosphate CH.OH c=o ніон ніон СН^РОзНя CHjOH I c=o HOCH нһон CH j OPO j H i Ribuloso-5-phosphate XyIulose-5-phosphate Another pentose - xylulose-5-phosphate, can be formed from ribulose-5- phosphate under the influence of the epimerase enzyme. Another pentose - xylulose-5-phosphate, can be formed from ribulose-5- phosphate under the influence of the epimerase enzyme. Hcptosis of sedoheptulose-7-phosphate is formed in the pentose cycle from xylulose-5-phosphate and ribose-5-phosphate as a result of a reaction catalyzed by the enzyme of transketolase. Xylulose-5-phospbate RJbqse-5-phosphate ! CHjOH ; 1 1 |c=o > 4 ♦ _ V 1 V ------ 1 H-C-OH Transketolase | HO-C-OH + 1 H-C-OH - ---- > H-C-OH + H-C-OH 1 H-C-OH HjC-OPOjHi H j C-OPO j H i HjC-OPOjHi PhoSphoglyceraldehyde CHjOH I C=0 HO-C-OH H-C-OH H-C-OH I H-C-OH t H j C-OPO j H j Sedoheptulose-7-phosphate Tetrose - erythrose-4-phosphate - occurs in the presence of transaldolase as a result of breaking the C%C bond in sedoheptulose with the transfer of the CH 2 OH%CO 3 /4 CHOH group to phosphoglycerol aldehyde: 234