Chapter 25.4, Problem 2QQ

Interpretation Introduction

Interpretation: To determine the molecule that shuttles activated fatty acid molecules across the inner mitochondrial membrane.

Concept introduction: Fatty acids are molecules that are long hydrocarbon chain of carboxylic acid. They are building blocks of fat in humans and animals.

The fatty acids are broken down to provide energy. The breakdown of fatty acids is a three parts process. In the first part, the fatty acid is activated. In the second part, the transportation of fatty acid into the mitochondrial matrix is facilitated by a shuttle mechanism. In the third part, the fatty acid is readily oxidized, cycling through a series of four reactions. $\text{Acetyl CoA}$, ${\text{FADH}}_2$, and NADH are produced in this reaction.

The first stage of fatty acid oxidation is the activation of fatty acids in the outer mitochondrial membrane. The fatty acid is activated by $\text{CoA}$ and ATP. The $\text{activated fatty acid}-\text{CoA}$ is called $\text{acyl CoA}$.