Describe the structure of a triacylglyceride

Triacylglycerides are a type of lipid composed of a glycerol head and three fatty acid tails. The fatty acid tails are long hydrocarbon chains which are non polar and so hydrophobic, and this is what causes lipids to be insoluble in water. The fatty acids can be either saturated or unsaturated. Saturated hydrocarbon chains do not contain any double bonds (i.e. the chain is saturated with hydrogen and cannot contain any more). Whereas unsaturated hydrocarbon chains do contain double bonds, and these double bonds cause a kink in the tail which affects the properties of the lipid (as the hydrocarbon chains cannot pack as closely together, resulting in weaker intermolecular interactions). The fatty acid tails are linked to the glycerol head via ester bonds which are formed in condensation reactions and can be broken in hydrolysis reactions.