Question

How many cycles of \(\beta\) oxidation are required for the complete oxidation of activated oleic acid, \(18: 1\left(\Delta^{9}\right)\) ?

Short answer

8 cycles are needed for the complete oxidation of oleic acid.

Step-by-step solution

Understand the Formula

Oleic acid is an 18-carbon fatty acid with one double bond at the 9th position, represented as \(18:1(\Delta^9)\). \(\beta\) oxidation involves breaking down fatty acids two carbons at a time. Our goal is to find out how many cycles are needed to fully oxidize this fatty acid.

Calculate Cycles for Saturated 18-Carbon Fatty Acid

For an 18-carbon saturated fatty acid, each cycle of \(\beta\) oxidation removes 2 carbons. To completely oxidize an 18-carbon chain, 8 cycles are required: \(\frac{18}{2} - 1 = 8\).

Adjust for the Double Bond

The presence of a double bond at position 9 requires one less step of \(\beta\) oxidation because when the double bond is present, this changes the energy and reduction steps needed slightly. However, since the double bond at the 9 position is in a location that does not alter the shortening sequence notably beyond an intermediate, saturated state, the number of cycles remains the same as for a similar saturated chain.

Confirm the Number of Cycles

Despite the modification in energetics due to the double bond treatment (an isomerization step is required), the total number of breakage cycles for \(\beta\) oxidation process remains 8. The cycles count comes solely from the total carbon length when the final cyclase conventionally aligns the chain.

Key concepts

Fatty Acid Metabolism

Fatty acid metabolism is a crucial process by which the body breaks down fatty acids to produce energy. This process primarily occurs in the mitochondria of cells, where lipids are converted into acetyl-CoA units through a series of reactions known as beta (\(\beta\)) oxidation.
During \(\beta\) oxidation, fatty acids undergo cyclic removal of carbon units in the form of acetyl-CoA. Each cycle of \(\beta\) oxidation reduces the carbon chain by two atoms and generates energy in the form of NADH and FADHyielding high-energy molecules used by the body.
The entire process results in vital components for the Krebs cycle, wherein acetyl-CoA is further oxidized to release even more energy. This oxidation is essential for the efficient use of stored fats within the body, especially when energy demands are high, such as during prolonged exercise or fasting.

• Fatty acid metabolism helps maintain energy balance.
• It produces reducing agents used in the electron transport chain.
• It supplies acetyl-CoA for the Krebs cycle.

Unsaturated Fatty Acids

Unsaturated fatty acids differ from saturated fatty acids in that they contain one or more double bonds within their carbon chain. These double bonds introduce kinks that influence the physical properties of the fatty acid.
For instance, oleic acid, a common unsaturated fatty acid with the structure denoted as \(18:1(\Delta^9)\), possesses a single double bond between the 9th and 10th carbon atom. This double bond affects not only the molecule's shape but also its reaction profile during metabolic processes.
In \(\beta\) oxidation of unsaturated fatty acids, the presence of double bonds introduces additional steps that are not present in the breakdown of saturated fatty acids. These may involve isomerization or reduction steps to convert the fatty acid into an appropriate form for regular \(\beta\) oxidation. This ensures that the unsaturated fatty acids can be metabolized for energy but may require fewer cycles due to their structural makeup.

• Double bonds affect the breakdown process.
• Special steps accommodate the unsaturation during \(\beta\) oxidation.
• They generally offer beneficial health effects due to unique structural properties.

Biochemistry Processes

Biochemistry processes such as \(\beta\) oxidation highlight the complexity and efficiency of cellular metabolism. The \(\beta\) oxidation pathway specifically showcases the integration of different enzymes and reactions to maintain energy homeostasis via lipid metabolism.
The stepwise breakdown involves dehydrogenation, hydration, another round of dehydrogenation, and thiolysis. Each smaller reaction within this pathway couples with NAD+ and FAD to form NADH and FADH2, capturing energy that powers further cellular processes.
These biochemistry processes adapt to various conditions the body encounters, modulating according to the availability of substrates such as unsaturated fatty acids. By understanding these processes, scientists and medical professionals can better comprehend disorders related to metabolic dysfunctions, such as those encountered in diabetes or obesity.

• \(\beta\) oxidation occurs in the mitochondria.
• It is a sequence of oxidation and reduction reactions.
• Enzyme efficiency is crucial to energy production.