Semmelweis Medicine Biology Entrance Practice Exam

Lipids are known for their high energy content, which makes them a significant energy source for the body. In terms of energy storage, lipids provide about 9 calories per gram, which is more than double the energy provided by carbohydrates, which yield approximately 4 calories per gram. This high energy density allows organisms to store more energy in a smaller volume compared to carbohydrates. Additionally, lipids play an essential role in thermal insulation, helping to maintain body temperature by providing a protective layer of fat under the skin or around vital organs.

This unique combination of high energy storage and thermal insulation makes lipids particularly advantageous for long-term energy reserves in living organisms, as well as for maintaining body heat in colder environments. Thus, the key advantage highlighted in the correct choice reflects both the energetic and insulating properties of lipids compared to carbohydrates.