Question

The enzyme GGPPS catalyzes three reactions to take DMAPP and isopentenyl diphosphate to form the final C20 product. From what you know now about enzymes, which statement is incorrect? A) The tertiary structure of the active site of GGPPS seems to fit isoprenoid products up to C20. B) The inhibitor zaragozic acid C, or at least a part of it must be similar to a C15 isoprenoid to "fool" the enzyme and stop the modification of farnesyl diphosphate. C) Zaragozic acid C could be used in metabolic studies involving C15 isoprenoid biosynthesis. D) Zaragozic acid seems to act as an allosteric inhibitor. E) I don't have enough information to make an educated guess, I mean, opinion The enzyme GGPPS catalyzes three reactions to take DMAPP and isopentenyl diphosphate to form the final C20 product. From what you know now about enzymes, which statement is incorrect? A) The tertiary structure of the active site of GGPPS seems to fit isoprenoid products up to C20. B) The inhibitor zaragozic acid C, or at least a part of it must be similar to a C15 isoprenoid to "fool" the enzyme and stop the modification of farnesyl diphosphate. C) Zaragozic acid C could be used in metabolic studies involving C15 isoprenoid biosynthesis. D) Zaragozic acid seems to act as an allosteric inhibitor. E) I don't have enough information to make an educated guess, I mean, opinion

Answer 1

DMAPP + Isopentenyl diphosphate (C5) ⇌ Geranyl diphosphate (C10)
IPP + Geranyl diphosphate (C10) ⇌ Farnesyl diphosphate (C15)
IPP + Farnesyl diphosphate (C15) ⇌ Geranylgeranyl diphosphate (C20)

D.Zaragozic acid C is a competitive inhibitor of GGPPS in the conditions for reaction iii)