Question

溜貍 A. co CO c0, Amino ades Amino acks Faity adds ET.C s-s of bacterial metabolism. The pathways are simplified: only key compounds are shown. ClM, cell membrane on transport chain; PS, photosystem. Notice that the reactions are not stoichiometrically balanced
Based on these metabolic pathways, what is there source of electrons for obtaining NADPH? What are the donors and acceptors in the electron transport chain?

Answer 1

Answer:- In these metabolic pathways the source of electrons for obtaining NADPH, the electrolysis of H2S and H2O.

through the electrolysis H2O and H2S donate e- to NADP+ and form NADPH. NADP+ is an oxidized form and NADPH is a reduced form .when the e- donated by H2O and H2S in matabolic pathways of bacteria than NADP+ accept the e- and change into its reduced form NADPH.

As there are two type of bacteria based on oxygen present in environment or not first aerobic if oxygen is present in environment or second anaerobic, if oxygen is not present in environment.

Electron donor :- if the oxygen is present in enviroment for most of eukaryotic bacteria, the electron donor is NADH.

NADH --complex I---Q --Complex III --- cytochrome C --- Complex IV --- O2.

But if oxygen is not available in environment the donors are different organic and inorganic compounds such as lactate e. t. c.

Electron acceptor:- if the oxygen present is present in enviroment, the acceptor is invariably oxygen because it generates the greatest gibbs free energy.

But in anaerobic enviroment different e-acceptors are used including nitrate, nitrite, ferric ion, sulfate, carbon dioxide and small organic molecules such as fumerate.
In aerobic condtion 2. FAD NADH quinont oxidae NAOH- quinone. 干