Question

Caprylic acid, CH₃-(CH₂)₄-CH₂-CH₂-COOH, is a fatty acid.

Answer 1

Answer:

a. See figure 1

b. See figure 2

c. Three cycles

d. Four Acetyl-CoAs

Explanation:

a. Draw the condensed structural formula for the activated form of caprylic acid

For the activation of the fatty acid, an ATP molecule is needed to bind AMP in the acid group and then an Acetyl-CoA molecule to generate the activated fatty acid. (See figure 1)

b. Indicate the α- & β-carbon atoms in caprylic acid

By definition, the alpha and beta carbons are the carbons that are in positions 2 and 3 respectively to the main carbon. In this case, the main carbon is the carbon from the acid group, therefore the alpha carbon will be carbon 2 (red arrow) and the beta carbon will be carbon 3 (blue arrow). (See figure 2).

c. State the number of β-oxidation cycles for the complete oxidation of caprylic acid.

To calculate the cycles we have to use the equation:

$Number~of~cycles:\frac{n}{2}-1$, where n is the amount of carbons, in this case, we have 8 carbons, so:

$Number~of~cycles:\frac{8}{2}-1=3$

We will have 3 cycles. (See figure 3)

d. State the number of acetyl-CoAs from the complete oxidation of caprylic acid

In the β-oxidation metabolic cycle, we have a relationship between Acetyl-CoA produced and the number of carbons:

$Number~of~Acetyl~Coas:\frac{n}{2}$ if n=8 we will have:

$Number~of~Acetyl~Coas:\frac{8}{2}=4~Acetyl~Coas$

We will have 4 Acetyl-CoAs.

I hope it helps!