Chapter 22, Problem 22.50E

Interpretation Introduction

(a)

Interpretation:

The balanced reaction for $\text{OH}-{\text{CH}}_{\text{2}}-\text{COOH}\to \text{O}=\text{CH}-\text{COOH}$ oxidations using ${\text{NAD}}^{+}$ or FAD is to be predicted.

Concept introduction:

The full form of ${\text{NAD}}^{+}$ molecule is nicotinamide adenine dinucleotide. ${\text{NAD}}^{+}$ is a coenzyme which contains two nucleotides joined together by phosphate groups. It carries the electrons from citric acid cycle to the electron transport chain.

Answer to Problem 22.50E

The balanced reaction for $\text{OH}-{\text{CH}}_{\text{2}}-\text{COOH}\to \text{O}=\text{CH}-\text{COOH}$ oxidations using ${\text{NAD}}^{+}$ is shown below.

$\text{OH}-{\text{CH}}_{\text{2}}-\text{COOH}+{\text{NAD}}^{+}\to \text{O}=\text{CH}-\text{COOH}+\text{NADH}$.

Explanation of Solution

The oxidation reaction is given as $\text{OH}-{\text{CH}}_{\text{2}}-\text{COOH}\to \text{O}=\text{CH}-\text{COOH}$.

In the above reaction, the alcohol group is oxidized to aldehyde group. The oxidation reaction by ${\text{NAD}}^{+}$ involves the oxidation of alcohol into aldehyde. Therefore, the oxidation reaction is balanced by using ${\text{NAD}}^{+}$ as shown below.

$\text{OH}-{\text{CH}}_{\text{2}}-\text{COOH}+{\text{NAD}}^{+}\to \text{O}=\text{CH}-\text{COOH}+\text{NADH}$

Conclusion

The balanced reactions for $\text{OH}-{\text{CH}}_{\text{2}}-\text{COOH}\to \text{O}=\text{CH}-\text{COOH}$ oxidations using ${\text{NAD}}^{+}$ is shown below.

$\text{OH}-{\text{CH}}_{\text{2}}-\text{COOH}+{\text{NAD}}^{+}\to \text{O}=\text{CH}-\text{COOH}+\text{NADH}$.

Interpretation Introduction

(b)

Interpretation:

The balanced reaction for $\text{OH}-{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}-\text{OH}\to \text{OH}-\text{CH}=\text{CH}-\text{OH}$ oxidations using ${\text{NAD}}^{+}$ or FAD is to be predicted.

Concept introduction:

The full form of ${\text{NAD}}^{+}$ molecule is nicotinamide adenine dinucleotide. ${\text{NAD}}^{+}$ is a coenzyme which contains two nucleotides joined together by phosphate groups. It carries the electrons from citric acid cycle to the electron transport chain.

Answer to Problem 22.50E

The balanced reaction for $\text{OH}-{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}-\text{OH}\to \text{OH}-\text{CH}=\text{CH}-\text{OH}$ oxidations using FAD is shown below.

$\text{OH}-{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}-\text{OH}+\text{FAD}\to \text{OH}-\text{CH}=\text{CH}-\text{OH}+{\text{FADH}}_{\text{2}}$.

Explanation of Solution

The oxidation reaction is given as $\text{OH}-{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}-\text{OH}\to \text{OH}-\text{CH}=\text{CH}-\text{OH}$.

In the above reaction, the $-{\text{CH}}_{\text{2}}-{\text{CH}}_{\text{2}}-$ portion of $\text{1, 2-diethanol}$ is oxidized to $-\text{CH}=\text{CH}-$. The oxidation reaction by FAD involves the conversion of $-{\text{CH}}_{\text{2}}-{\text{CH}}_{\text{2}}-$ into $-\text{CH}=\text{CH}-$. Therefore, the oxidation reaction is balanced by using FAD as shown below.

$\text{OH}-{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}-\text{OH}+\text{FAD}\to \text{OH}-\text{CH}=\text{CH}-\text{OH}+{\text{FADH}}_{\text{2}}$

Conclusion

The balanced reaction for $\text{OH}-{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}-\text{OH}\to \text{OH}-\text{CH}=\text{CH}-\text{OH}$ oxidations using FAD is shown below.

$\text{HO}-{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}-\text{OH}+\text{FAD}\to \text{HO}-\text{CH}=\text{CH}-\text{OH}+{\text{FADH}}_{\text{2}}$.