1.2.2 Triglyceride Function

Saturated vs. Unsaturated Lipids:

• Saturated Lipids:
• Found in animal fats.
• These lipids do not contain any carbon-carbon double bonds in their fatty acid chains.
• They are typically solid at room temperature because the lack of double bonds allows the molecules to pack tightly together.

• Unsaturated Lipids:
• Found in plants.
• These lipids contain carbon-carbon double bonds, which cause the molecule to bend. This prevents the molecules from packing tightly, making them liquid at room temperature.

Triglyceride Structure and Function:

• Energy Storage: Triglycerides have a high ratio of carbon-hydrogen bonds to carbon atoms, making them an excellent source of energy. When oxidised, they release significant amounts of energy, more than carbohydrates or proteins.
• Efficient Storage: Triglycerides have a low mass-to-energy ratio, meaning they can store a lot of energy in a relatively small volume. This is particularly important for animals, as it reduces the overall mass they need to carry for energy reserves.
• Insolubility: Being large and non-polar, triglycerides are insoluble in water, so they do not affect the water potential of cells. This prevents water from entering cells by osmosis, avoiding any potential damage or swelling.
• Water Source: Due to their high hydrogen-to-oxygen ratio, triglycerides produce water when they are oxidised. This is an essential source of water for organisms living in dry environments, where water is scarce.