Question

Problem 1. Metabolism

Carotenoid-derived compounds such as ionones and pseudoionone constitute essential aromas in tea, roses, tomato, wine and tobacco. Pseudoionone is a valuable acyclic intermediate for the chemical synthesis of ionones. Thus, there has been several attempts to produce this compound in a heterologous host as shown below.

talB PPP NAD+ NADH NADP+ NADPH NADP+ NADPH Mal OAA Pyr GЗР 6PG- Ru5P Ac-Co Fum Cit NADPH dxs NADP+ FADH2 ola sdhABCD DXP TCA FAD Biosynthetic pathway of Pseudoionene Suc Isocit MEP АТР, crtEIB ATP SUCAB AKG B241 Suc-COA NAD IPP Lycopene ADP ADP NADH NADH HMBPP idi NAD cmCCD1 NADPH NADP+ DMAPP - Pseudoionones

In the figure above the enzymes (here shown as gene names) are given in Italics and chemical compounds in non-italics.

The figure shows that pseudoionones are produced from the general terpenoid pathway that branches off the glycolytic central metabolism pathway at pyruvate (Pyr) and glyceraldehyde-3-phosphate (G3P).

g)Mention the two alternative pathways in E. coli that can oxidize glucose into glyceraldehyde-3-phosphate and eventually pyruvate

Answer 1

Ans. - Two alternative pathway in S. coli that can oxidise glucose in to g Cy ceral dehyde - 3-P and eventually bysurate is following- 1) Glycolysis pathway. In this pathway glucose ender goes maltiple step (10) and form byruvate intermediate Glycesa (dehyde-g-P also formed. Cou to Glyceraldehyde-a-p bre Pyruvate. erly ceraldehyde a 2) Pento phosphate pathway (App) It is alternative pathway in which Glucose can again go to 3-P with Rubulose-5-phosphate, and finally into bysarate. Glucose 6PG Rå5P Gly-3-1 - Pyruvate. (Ribulole.5. Phorphet)