Chapter 24, Problem 5P

Interpretation Introduction

Interpretation:

Stoichiometry of the stearoyl-CoA desaturase should be convinced correct.

Concept Introduction:

In eukaryotes, addition of double bond to fatty acids does not occur until the fatty acid chain occupied its full length. But the dehydrogenation of stearoyl-CoA occurs in the middle of the chain

  ${\text{Stearoyl-CoA + NADH + H}}^{+}{\text{ + O}}_2\to {\text{ Oleoyl-CoA + 2 H}}_2\text{O}$

Above reaction is catalyzed by stearoyl-CoA desaturase enzyme. This enzyme has a nonheme iron center. NADH and O₂ is required to run this reaction. As well as, two other proteins cytochrome b₅ reductase and cytochrome b₅ are needed. These three proteins are incorporated with ER membrane.