Consider the complete oxidation of palmitoleic acid, CH₃ ― (CH₂)₅ ― CH = CH ― (CH₂)₇ ― COOH, which is a C₁₆ monounsaturated fatty acid found in animal and vegetable oils..
a. How many cycles of β oxidation are needed?

Verified step by step guidance

1. Identify the total number of carbon atoms in palmitoleic acid. Palmitoleic acid is a C₁₆ fatty acid, meaning it contains 16 carbon atoms.
2. Determine the number of carbons removed per cycle of β-oxidation. Each cycle of β-oxidation removes a two-carbon unit in the form of acetyl-CoA.
3. Calculate the total number of β-oxidation cycles required. Since each cycle removes 2 carbons, divide the total number of carbons (16) by 2. However, note that the final cycle produces two acetyl-CoA molecules, so the number of cycles will be one less than the total number of two-carbon units.
4. Account for the presence of the double bond in the monounsaturated fatty acid. The double bond requires an additional step involving an isomerase enzyme to convert the cis double bond to a trans configuration, which allows β-oxidation to proceed normally.
5. Combine the results to determine the total number of β-oxidation cycles needed, considering the adjustment for the double bond and the final cycle producing two acetyl-CoA molecules.

Key Concepts

Beta Oxidation

Beta oxidation is a metabolic process that breaks down fatty acids into acetyl-CoA units, which can then enter the citric acid cycle for energy production. Each cycle of beta oxidation shortens the fatty acid chain by two carbon atoms and produces one molecule of acetyl-CoA, along with NADH and FADH2, which are used in the electron transport chain.

Monounsaturated Fatty Acids

Monounsaturated fatty acids (MUFAs) contain one double bond in their carbon chain. In the case of palmitoleic acid, the presence of a double bond affects the number of beta oxidation cycles required, as the double bond must be isomerized before further oxidation can occur. This is crucial for determining the total cycles needed for complete oxidation.

Fatty Acid Oxidation Calculation

To calculate the number of beta oxidation cycles for a fatty acid, the formula is (n/2) - 1, where n is the number of carbon atoms in the fatty acid. However, for monounsaturated fatty acids, an additional step is needed to account for the double bond, which may require one less cycle due to the need for isomerization. This calculation is essential for determining the energy yield from the fatty acid.