Classification of Fatty Acids Flashcards

Lipids and Fatty Acids

• Lipids are a diverse group of compounds vital to biochemistry.
• They are hydrophobic, being insoluble in water but soluble in non-polar solvents like benzene and ether.
• Fatty acids are a primary component of lipids and are derived lipids.
• Hydrolysis involves reactions where ethanolic KOH interacts with oils to produce glycerol and fatty acids.
• Most fatty acids combine with glycerol to form triglycerides; they do not exist freely in nature.

Structure and Classification of Fatty Acids

• Each fatty acid has one carboxyl group and a non-polar hydrocarbon tail, contributing to their hydrophobic nature.
• The carboxyl group (COOH) is the functional group that defines chemical properties, while the hydrocarbon chain (R group) influences physical properties.
• Triglycerides are created through the esterification process between glycerol and fatty acids.
• Palmitic and stearic acids are the most prevalent fatty acids in the human body.

Essential Fatty Acids and Metabolism

• Acetic and butyric acids are key metabolic intermediates.
• Polyunsaturated fatty acids can exhibit geometric isomerism at double bonds.
• Linoleic acid contains two double bonds and is essential since humans cannot synthesize it.
• Most unsaturated fatty acids primarily exist as unstable cis isomers instead of stable trans isomers.
• Cis isomers are curved, whereas trans isomers remain straight.

Synthesis and Function of Fatty Acids

• Oleic acid can be synthesized from stearic acid, but humans cannot create linoleic or linolenic acids beyond the ninth carbon.
• Arachidonic acid can be synthesized from linoleic acid, which serves as a precursor for various eicosanoids.
• Eicosanoids are defined by having twenty carbon atoms and exhibit hormone-like actions locally where they are synthesized.

Eicosanoids and Their Role

• Eicosanoids are classified into two categories: prostanoids and leukotrienes.
• They function primarily at their synthesis sites, affecting local physiological processes.
• Three primary sources of fatty acids include dietary intake, essential fatty acids, and body synthesis.
• Activators of phospholipase A2 include histamine and cytokines.

Pharmacological Implications

• Misoprostol, a synthetic PGE1 analogue, is utilized to protect against gastric acid in patients using aspirin or NSAIDs.
• Prostaglandin I counteracts thromboxane actions.
• Leukotrienes are synthesized in various cell types and play significant roles in inflammatory responses, particularly in asthma and bronchitis.
• Prostaglandins have a short half-life of around five minutes, while leukotrienes can last for hours in tissues and contribute to prolonged bronchoconstriction in asthma.
• Zileuton, an inhibitor of 5-lipooxygenase, is used for treating ulcerative colitis.
• Montelukast and zafirlukast are leukotriene receptor antagonists that block leukotrienes' effects.

This set of flashcards covers the classification of fatty acids and their biochemical importance. It includes definitions of key terms related to lipids and their solubility properties. Enhance your understanding of lipid chemistry with these essential concepts.