Question

5. Calculate approximately how many molecules of ATP could be synthesized from the complete oxidation of glucose( delta G'^o = -2840 kJ/mol). Revisit this estimate later.

6. what is the significance of the various categories of electron carriers (water-soluble vs. lipid-soluble; mobile vs. bound; associated with peripheral vs. integral membrane proteins) in terms of an electron carrier's functions?

7. How do the normal concentration ratios of NAD⁺/NADH and NADP⁺/NADPH in cells reflect the different metabolic roles of these electron carriers?

Answer 1

5

Let's see; the total energy available from glucose is 2840 kJ/ mol. Delta G for ATP hydrolysis is 30.543 kJ/mol. But under cellular conditions, it is 41.8 kJapproximatelyimatly, 41.8-58.57). So there should be 67.8 (68) moles of ATP generated. However, due to loss only 36-38 moles generated, an efficiency of 52-55 percent

6) Water-soluble carriers can be mobile in the cytoplasm like cytochrome c which transfers electrons to oxygen directly and hence is the link to oxygen in aerobic respiration. Whereas lipid-soluble can function within the membrane itself, they are generally bound and hydrophobic like Flavoproteins and Coenzyme Q. Complexes I, III, and IV are integral proteins, they span across the membrane and hence aid in the intermembrane transfer of H+ ions. This proton gradient is later used in the generation of ATP. They form hydrophilic trans-membrane channels.

7) NADH is the reduced form and the ratio of free NAD+/NADH is around 700, giving away that it maintains apt conditions for oxidative reactions. NADP+/NADPH ratio is around 0.005, thus favoring reduction reaction. There exists a balance between them to maintain the redox state of the cell.