The carbon double bonds in any unsaturated hydrocarbon chains are monounsaturated or polyunsaturated and their presence causes the fatty acid tails to bend slightly.
Saturated fatty acids can pack together very tightly due to their straight chain structure, while unsaturated fatty acids push further apart due to their bends in the tail.
A saturated fatty acid in a triglyceride has no carbon-carbon double bonds and exists as a solid at room temperature, while a monounsaturated fatty acid found in a triglyceride has one double carbon bond and exists as a liquid at room temperature.
Unsaturated fatty acids have bends in their fatty acid chains that push each other away, increasing the space between the molecules and weakening the intermolecular forces.
Polyunsaturated fatty acids have many double bonds and exist as a liquid, while triglycerides have a range of different functions in the body, including being used in respiration.
The triglyceride molecule is made up of the glycerol with three fatty acids, and when these are broken down, they form two components: the glycerol and the fatty acids.