Question

If an animal needed to store lots of energy for long-term use, but not be encumbered with the weight of lots of extra tissue, which is the best molecule for storage?

A) fructose and glucose in the form of honey
B) high-calorie fat molecules
C) starch
D) complex cellulose molecules
E) glycogen with extensive side branches of glucose

Answer 1

High-calorie fat molecules are the best for long-term energy storage in animals due to their energy density and lighter weight per calorie stored compared to glycogen or other carbohydrates.

Step-by-step explanation:

The best molecule for an animal to store a lot of energy for long-term use without being encumbered with the weight of extra tissue is high-calorie fat molecules. Fats are more energy-dense than carbohydrates or proteins and provide a significant amount of energy in a compact form. While glycogen serves as the primary short-term glucose store in animals, fats are the primary form of long-term energy storage. This is because fats are more hydrophobic than carbohydrates and do not bind water, which makes them lighter per stored calorie compared to glycogen or other carbohydrates. Additionally, fats yield about 9 calories per gram, whereas carbohydrates like glycogen yield about 4 calories per gram, making fats a more efficient storage form for energy.