102 handout 1018 KEY - Δ Δ Note the reduction of NAD can...

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
For each of the following pairs of half-reactions, what the net reaction and the free energy change? Fumarate + 2H + + 2e - Succinate E’° = 0.03 V FAD + 2H + + 2e - FADH 2 E’° = - 0.22 V FADH 2 FAD + 2H + + 2e - E’° = 0.22 V Fumarate + FADH 2 FAD + succinate E’° = 0.25 V Δ Electrons flow from FADH 2 to fumarate. G’° = -nF E’° = -2 (96.5 kJ/V·mol) (0.25V) = -48.25 kJ/mol Δ Δ Note: the reason this reaction goes in reverse in the citric acid cycle is that the actual E’° of FAD when bound to the enzyme is much lower (~0.03 V), which makes the E’° and thus Δ the G’° for this reaction about zero. Therefore, it is readily reversible especially when Δ levels of succinate are high and/or levels of fumarate are low. Acetaldehyde + 2H + + 2e - Ethanol E’° = - 0.20 V N AD + + 2H + + 2e - NADH + H + E’° = - 0.32 V NADH + H + NAD + + 2H + + 2e - E’° = 0.32 V Acetaldehyde + NADH + H + Ethanol + NAD + E’° = 0.12 V Δ Electrons flow from NADH to acetaldehyde. G’° = -nF
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Δ Δ Note: the reduction of NAD + can also be written as NAD + + H + + 2e-NADH and has the same E’° as above (-0.32 V). If C-1 of ribulose 5-phosphate is labeled with 14 C, at which position(s) does the label appear in sedoheptulose 7-phosphate? Carbons 1 and 3 If C-2 of ribulose 5-phosphate is labeled with 14 C, at which position(s) does the label appear in erythrose 4-phosphate? Carbon 1 If C-3 of ribulose 5-phosphate is labeled with 14 C, at which position(s) does the label appear in sedoheptulose 7-phosphate? in GAP? Carbon 5 of sedoheptulose 7-phosphate and carbon 1 of GAP If C-4 of ribulose 5-phosphate is labeled with 14 C, at which position(s) does the label appear in erythrose 4-phosphate? in fructose 6-phosphate? Carbon 3 of erythrose 4-phosphate and carbon 5 of fructose 6-phosphate...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern