Answer:
Alpha- ketoglutarate --> NADP+ --> Oxaloacetate --> O2.
(O2 has the HIGHEST tendency to donate electrons).
Step-by-step explanation:
Okay, we are to Arrange Alpha- ketoglutarate, Oxaloacetate ,O2, NADP+ and Malate in order of increasing tendency to donate electrons, therefore, the correct order is;
Alpha- ketoglutarate --> NADP+ --> Oxaloacetate --> O2.
And this result can be gotten if we consider these compounds in their oxidative mechanism and check their potential values.
(1). When Alpha- ketoglutarate react with CO2, it gives isocitrate and standard redox potential value of -0.38.
(2). NADP+ with react with two moles of electrons and one mole of hydrogen ion to produce NADPH and standard redox potential value of -0.32.
(3). Oxaloacetate will react with two moles of hydrogen ion and electrons respectively to produce standard redox potential value of -0.18 and Malate.
(4). O2 will react with 4 moles of hydrogen ion and electrons respectively to produce 2 moles of water and standard redox potential value of +0.82.
CONCLUSION: the higher the negative values of the potential, the lesser the electron affinity and vice versa.