Which molecule makes up the backbone of all triglycerides?
Eicosanoid
Glycerol
Phospholipid
Fatty acid
The correct answer and explanation is:
The correct answer is Glycerol.
Triglycerides are a type of lipid made up of three fatty acid molecules bound to a glycerol backbone. The structure of a triglyceride consists of one glycerol molecule, which is a three-carbon compound, each attached to a fatty acid chain through ester linkages. Each fatty acid chain is a long hydrocarbon chain with a carboxyl group (-COOH) at one end. The esterification process happens when the hydroxyl groups (-OH) on glycerol react with the carboxyl group of each fatty acid, releasing water molecules in the process.
Glycerol serves as the structural backbone of triglycerides. It is hydrophilic (water-attracting) because of its hydroxyl groups, while the fatty acids attached to it are hydrophobic (water-repellent). This combination of properties makes triglycerides non-polar and largely insoluble in water. Triglycerides are found in fats and oils and are the most common form of stored energy in the body.
Fatty acids, on the other hand, are not the backbone but rather the components attached to the glycerol molecule. Phospholipids and eicosanoids are other types of lipids that have different roles and structures. Phospholipids, for example, are important in forming the bilayer structure of cell membranes, while eicosanoids are signaling molecules derived from fatty acids that play roles in inflammation and other processes.
In summary, glycerol is the key molecule that forms the backbone of all triglycerides, connecting the three fatty acids to create the triglyceride molecule, which is essential for energy storage and insulation in living organisms.