Chemistry and Functions of Lipids

Common Properties of Lipids

• Lipids are hydrophobic or amphipathic, meaning they repel water or can have both hydrophilic and hydrophobic parts.
• They are generally insoluble in water but soluble in organic solvents.

Main Function as Thermal Insulators

• Lipids provide insulation by trapping heat, helping to maintain body temperature in cold environments.
• They reduce heat loss through the skin by acting as a barrier.

Functions NOT Associated with Lipids

• Structural support is primarily a function of proteins, while lipids are mainly involved in energy storage, insulation, and signaling.

Role of Lipoproteins

• Lipoproteins are complexes of lipids and proteins that transport lipids through the bloodstream.
• They play a critical role in lipid metabolism and distribution throughout the body.

Diseases Linked to Lipid Metabolism

• Disorders such as hyperlipidemia or atherosclerosis are linked to abnormal lipid chemistry and metabolism.
• These conditions can lead to cardiovascular diseases due to high levels of lipids in the blood.

Example of a Compound Lipid

• Phospholipids are a common example of compound lipids, contributing to cell membrane structure and function.

General Formula for Saturated Fatty Acids

• Saturated fatty acids typically follow the formula CnH(2n+1)COOH, where n is the number of carbon atoms.

Fatty Acids with No Double Bonds

• Saturated fatty acids contain no double bonds between carbon atoms, resulting in a fully saturated structure with hydrogen.

Characteristic of Small Chain Fatty Acids

• Small chain fatty acids (typically fewer than six carbon atoms) are more soluble in water due to their shorter hydrocarbon chain.

Lipid Molecules from Hydrolysis

• Glycerol can be derived from the hydrolysis of simple and compound lipids.