Which macromolecules store the most energy

Subject : Biology

Question:

Which macromolecules store the most energy?

A: proteins

B: carbohydrates

C: nucleic acids

D: lipids

Expert Verified Solution:

The macromolecules that store the most energy are D: lipids. Lipids, which include fats, oils, and triglycerides, are rich in energy because they contain long chains of hydrocarbons. These hydrocarbon chains store a large amount of energy that is released when they are broken down during metabolic processes.

In comparison, carbohydrates and proteins store less energy per gram because their molecular structures are less dense in energy-rich bonds. Nucleic acids, on the other hand, primarily serve genetic functions and are not significant energy storage molecules.

Lipids are essential for long-term energy storage in organisms. For instance, fat stores in animals provide a reservoir of energy that can be accessed during periods of fasting or when immediate energy sources like carbohydrates are depleted. This makes lipids the most efficient macromolecules for energy storage.