Q. 18.73 - An Introduction to General, Organic, and Biological Chemistry

Question

Lauric acid is a ${\mathrm{C}}_{12}$ fatty acid found in coconut oil.

a. How many cycles of $\mathrm{\beta }$ oxidation are needed for the complete oxidation of lauric acid?
b. How many acetyl CoA are produced from the complete oxidation of lauric acid?
c. Calculate the total ATP yield from the complete $\mathrm{\beta }$ oxidation of lauric acid by completing the following:

Step-by-Step Solution

Answer

Part(a) Five cycles of $\mathrm{\beta }$ oxidation are needed.

Part(b) Six acetyl CoA are produced. 

Part(c)  

Activation		$\to -2 \mathrm{ATP}$
$6 \mathrm{acetyl} \mathrm{CoA}$	$\times 10 \mathrm{ATP}/\mathrm{acetyl} \mathrm{CoA}$	$\to 60 \mathrm{ATP}$
$5 \mathrm{NADH}$	$\times 2.5 \mathrm{ATP}/\mathrm{NADH}$	$\to 12.5 \mathrm{ATP}$
$5 {\mathrm{FADH}}_2$	$\times 1.5 \mathrm{ATP}/{\mathrm{FADH}}_2$	$\to 7.5 \mathrm{ATP}$
Total		$78 \mathrm{ATP}$

Part(a) Step 1 : Given information

We are given Lauric acid. We need to find cycles of $\mathrm{\beta }$ oxidation that are needed for the complete oxidation of lauric acid

Part(a) Step 2 : Simplify

As Lauric acid is ${\mathrm{C}}_{12}$ fatty acid and Structure of Lauric acid is

From the above structure, we can say Five cycles of $\mathrm{\beta }$ oxidation are needed for the complete oxidation of lauric acid.

Part(b) Step 1 : Given information

We are given Lauric acid. We need to find number of acetyl CoA produced from the complete oxidation of lauric acid.

Part(b) Step 2 : Simplify

Structure of lauric acid is

From the above structure, we can say Six acetyl CoA are produced from the complete oxidation of lauric acid .

Part(c) Step 1 : Given information

We are given Lauric acid. We need to calculate the total ATP yield from the complete $\mathrm{\beta }$ oxidation of lauric acid

Part(c) Step 2 : Simplify

The total ATP  yeild will be fom acetyl CoA , NADH, and FADH_{2 .}

Required table is :

Activation		$\to -2 \mathrm{ATP}$
$6 \mathrm{acetyl} \mathrm{CoA}$	$\times 10 \mathrm{ATP}/\mathrm{acetyl} \mathrm{CoA}$	$\to 60 \mathrm{ATP}$
$5 \mathrm{NADH}$	$\times 2.5 \mathrm{ATP}/\mathrm{NADH}$	$\to 12.5 \mathrm{ATP}$
$5 {\mathrm{FADH}}_2$	$\times 1.5 \mathrm{ATP}/{\mathrm{FADH}}_2$	$\to 7.5 \mathrm{ATP}$
Total		$78 \mathrm{ATP}$