0 ⑤脱水 CH3一CH=CH-C-S 反式丁烯酰ACP HS KS MT AT ACP KR CHg-CH一CH2-CS ER HD OH HS KS MT trans-A2.Butenovl-ACP AT ACP KR H20 ER HD dehydration B-羟脂酰-ACP脱水酶，D B-Hydroxybutyryl-ACP
⑤脱水 β-羟脂酰-ACP脱水酶，HD 反式丁烯酰ACP
CH3一CH2一CH2 丁酰ACP ⑥还原 HS KS MT AT ACP KR ER HD Butyryl-ACP NADP+ reduction of NADPH+H+ double bond CH3-CH-CH 烯脂酰-ACP还原酶，ER KS MT AT ACP KR ER HD trans-A2-Butenoyl-ACP
烯脂酰-ACP还原酶，ER ⑥还原 丁酰ACP
CH3一CH2TCH2 0 SH HS CH3-CH2一CH2-C一S KS MT KS MT ACP AT AT KR AT ACP KR ER HD ER HD Butyryl-ACP
AT
SH CH3-CH2—CH2 -O Butyryl group KS MT AT ACP R ER HD CH2 S-CoA Malonyl-CoA →CoA-SH 0 CH2一C CH3CH2—CH2 KS MT AT ACP R ER HD
0 CHa CH2 Malonyl group CH2 OH 0 HS Acetyl group CHa- (first acyl group) Fatty acid synthase dehydration 3 H.O C02 HS CH3-C-CH2 HS NADPH +H+ reduction 4 NADP+ NADPH +H+ CHs-CH2-CH2 reduction Saturated acyl group, lengthened by two carbons HS NADP+