Biochemistry-Gift-2-Spring-2019.

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NASA to do the biochemical write up on a new organism recovered from a Martian probe! During your analysis you have discovered a brand new electron transport chain! The organism appears to use elect... ron transport as its primary source of energy rather than ATP. This leaves you with a couple of questions to answer: During analysis, your technician reports a new electron transport chain (always check your technician’s work! Analyze this carefully!): Ickygreenone + H+ + 2e- → Ickygreenol [REDACTED] V -0.2 V Barsool → Barsoom + H+ + 2e- [REDACTED] V 0.03 V Because the reactions are not originally in the same form we would flip the bottom reaction to have the oxidized form accepting electrons to become the reduced form so we can determine which half reaction is the stronger reductant This would give: Ickygreenone + H+ + 2e- → Ickygreenol (-0.2 V) Barsoom + H+ + 2e- → Barsool (-0.03 V) Both half reactions are now in the same form so we can confirm that the top reaction is the most negative of the two half reactions and the stronger reductant **If we want to solve for ΔE we would flip the top reaction to make the electrons flow, 0 which would give: Ickygreenol → Ickygreenone + H+ + 2e- (0.2 V) Barsoom + H+ + 2e- → Barsool -0.03 V (-0.03 V) **to determine, reductant, oxidant, reduced, and oxidized you would look at the half reactions when they are in the same form (before the stronger reductant becomes flipped) So this: Ickygreenone + H+ + 2e- → Ickygreenol (-0.2 V) Barsoom + H+ + 2e- → Barsool (-0.03 V) 9. Which species is the reductant for the proposed ETC? Reductant relates to oxidized so Ickygreenol and Barsool are the reductants The stronger reductant would be Ickygreenol because it is the most negative **Smaller Ev value is more negative 10. Which species is the oxidant for the proposed ETC? Oxidant relates to being reduced so Ickygreenone and Barsoom are the oxidants because they have gained electrons ← this is just how I understand it The stronger oxidant would be Barsoom because it is the most “positive” **Larger Ev value is more positive 11. Which series of voltages represents the correct voltages to trace the electron flow for the free energy calculation? If this is what we originally had: Ickygreenone + H+ + 2e- → Ickygreenol (0.5 V) Barsoom + H+ + 2e- → Barsool (1.25 V) Then 0.5 would be flipped because it is the most “negative” out of the two voltages This means the top equation has the strongest reductant This would give: Ickygreenol → Ickygreenone + H+ + 2e- (-0.5 V) Barsoom + H+ + 2e- → Barsool (1.25 V) If this is what we originally had: Ickygreenone + H+ + 2e- → Ickygreenol (-0.5 V) Barsoom + H+ + 2e- → Barsool (-1.25 V) Then -1.25 would be flipped because it is the most “negative” out of the two voltages This means the bottom equation is the strongest reductant This would give: Ickygreenone + H+ + 2e- → Ickygreenol (-0.5 V) Barsool → Barsoom + H+ + 2e- (1.25 V) a) -0.5V and -1.25V b) +0.5V and -1.25V c) -0.5V and +1.25V d) +0.5V and +1.25V [Show More]

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