Caprylic acid, CH₃ ― (CH₂)₆ ― COOH, is a C₈ fatty acid found in milk.
a. State the number of β oxidation cycles for the complete oxidation of caprylic acid.

Verified step by step guidance

1. Step 1: Understand the process of β oxidation. β oxidation is the metabolic pathway where fatty acids are broken down into acetyl-CoA units. Each cycle of β oxidation removes a two-carbon unit from the fatty acid chain.
2. Step 2: Determine the number of carbon atoms in caprylic acid. Caprylic acid has the molecular formula CH₃ ― (CH₂)₆ ― COOH, which contains 8 carbon atoms in total.
3. Step 3: Recall that the first acetyl-CoA is formed without a β oxidation cycle, and subsequent cycles remove two carbons per cycle. To calculate the number of β oxidation cycles, subtract 2 carbons for the first acetyl-CoA, leaving 6 carbons to be processed.
4. Step 4: Divide the remaining number of carbons (6) by 2, as each β oxidation cycle removes two carbons. This gives the number of β oxidation cycles required to completely oxidize the fatty acid.
5. Step 5: Conclude that the number of β oxidation cycles corresponds to the number of times the fatty acid chain is shortened by two carbons until no carbons remain to be processed.

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, producing one molecule of acetyl-CoA and reducing equivalents in the form of NADH and FADH2.

Fatty Acid Structure

Fatty acids are carboxylic acids with long hydrocarbon chains. Caprylic acid, specifically, is an 8-carbon saturated fatty acid (C8), which means it has a straight chain of carbon atoms with hydrogen atoms filling the remaining valences. Understanding the structure is crucial for determining how many cycles of beta oxidation will occur.

Energy Yield from Fatty Acids

The complete oxidation of fatty acids yields significant energy, primarily through the production of ATP from acetyl-CoA in the citric acid cycle and the electron transport chain. Each cycle of beta oxidation generates energy carriers, and knowing the number of cycles helps calculate the total energy yield from the fatty acid.