Problem 31
Which of the following statements are true? For each, explain why or why not. (a) All coenzymes are electron-transfer agents. (b) Coenzymes do not contain phosphorus or sulfur. (c) Generating ATP is a way of storing energy.
Problem 33
The following half reactions play important roles in metabolism. \\[ \begin{array}{c} ^{1} / 2 \mathrm{O}_{2}+2 \mathrm{H}^{+}+2 e^{-} \rightarrow \mathrm{H}_{2} \mathrm{O} \\ \mathrm{NADH}+\mathrm{H}^{+} \rightarrow \mathrm{NAD}^{+}+2 \mathrm{H}^{+}+2 e^{-} \end{array} \\] Which of these two is a half reaction of oxidation? Which one is a half reaction of reduction? Write the equation for the overall reaction. Which reagent is the oxidizing agent (electron acceptor)? Which reagent is the reducing agent (electron donor)?
Problem 43
Show that the hydrolysis of ATP to AMP and \(2 P_{i}\) releases the same amount of energy by either of the two following pathways. Pathway 1 \\[ \begin{array}{l} \mathrm{ATP}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{ADP}+\mathrm{P}_{\mathrm{i}} \\ \mathrm{ADP}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{AMP}+\mathrm{P}_{\mathrm{i}} \end{array} \\] Pathway 2 \\[ \begin{array}{c} \mathrm{ATP}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{AMP}+\mathrm{PP}_{\mathrm{i}}(\text { Pyrophosphate }) \\ \mathrm{PP}_{\mathrm{i}}+\mathrm{H}_{2} \mathrm{O} \rightarrow 2 \mathrm{P}_{\mathrm{i}} \end{array} \\]
