Describe the structure properties and biologica... - SS3 Chemistry Organic Chemistry: Carbohydrates and Lipids Question

Structure of Fatty Acids:

Fatty acids are the building blocks of lipids. They are long-chain hydrocarbons with a carboxylic acid group (COOH) at one end. The hydrocarbon chain can vary in length and may be saturated (containing only single bonds between carbon atoms) or unsaturated (containing one or more double bonds). Fatty acids can be classified based on the presence of double bonds as saturated fatty acids (no double bonds), monounsaturated fatty acids (one double bond), or polyunsaturated fatty acids (multiple double bonds).

Properties of Fatty Acids:

1.    Hydrophobic Nature: Fatty acids are hydrophobic due to their long hydrocarbon tails, which repel water molecules. This property makes them insoluble in water but soluble in nonpolar solvents like alcohol and ether.

2.    Melting Point: The melting point of fatty acids depends on the length of the hydrocarbon chain and the degree of unsaturation. Saturated fatty acids have higher melting points than unsaturated fatty acids of the same chain length, as the straight-chain structure of saturated fatty acids allows for closer packing.

3.    Biological Activity: Fatty acids play crucial roles in various biological processes, including energy storage, membrane structure, and cell signalling.

Biological Significance of Fatty Acids:

1.    Energy Storage: Fatty acids are the primary energy storage form in the body. Excess dietary energy is converted into triglycerides, where three fatty acids are esterified to a glycerol backbone, for storage in adipose tissue.

2.    Membrane Structure: Fatty acids are essential components of phospholipids, the building blocks of cell membranes. The hydrophobic fatty acid tails face inward, forming a lipid bilayer that acts as a selectively permeable barrier between the cell and its environment.

3.    Precursors for Signalling Molecules: Certain fatty acids, particularly omega-3 and omega-6 polyunsaturated fatty acids, are precursors for the synthesis of important signalling molecules, such as prostaglandins and leukotrienes, which are involved in inflammation, blood clotting, and immune responses.