Pronunciation: [lˈɪpa͡ɪd] (IPA) 
The spelling of "lipide" may seem unusual to some, but it is an accepted variant of the more commonly used "lipid". In IPA phonetic transcription, the word is pronounced /ˈlɪpaɪd/ or "LIP-ide". The extra "e" at the end of the word is likely due to its origin in French, where it is spelled "lipide". Despite the different spelling, both versions of the word refer to the same organic molecules that make up fats and oils in living organisms.
Lipide, also known as lipid, is a broad term used to describe a diverse group of biological compounds that are insoluble in water but soluble in organic solvents such as alcohol, ether, or chloroform. Lipids play an essential role in living organisms, serving as a major component of cell membranes, a source of energy, and a precursor for various bioactive molecules.
Lipids are composed of carbon, hydrogen, and oxygen atoms that are arranged into three main subcategories: triglycerides, phospholipids, and sterols. Triglycerides, the most common form of lipids, are comprised of three fatty acid molecules attached to a glycerol backbone. They function as an energy storage molecule in adipose tissue. Phospholipids, on the other hand, consist of two fatty acid chains connected to a glycerol molecule and a phosphate group. These lipids form the structural basis of cell membranes, creating a phospholipid bilayer that separates the cell from its environment. Lastly, sterols, such as cholesterol, are a subgroup of lipids that play crucial roles in hormone production and membrane fluidity.
Lipids are not only involved in energy storage and structural support but also participate in various biological processes like cellular signaling, insulation, and protection of organs. Imbalances in lipid metabolism can result in disorders such as obesity, cardiovascular diseases, and insulin resistance. Thus, understanding lipids and their functions is imperative for comprehending the complexities of biological systems.
The word lipide is derived from the French term lipide, which was coined by the French biochemist and Nobel laureate, Claude Bernard, in 1847. Bernard used the word lipide to describe the fat-like substances he observed while studying digestion. The term originates from the Greek word lipos, which means fat or grease.
