What structural
tructural difference explains why lipids provide more energy to a cell than an equal mass
of proteins or carbohydrates?
Lannroteins or carbohydrates.

The presence of more C-H bonds in lipids.

Explanation:

Lipids have more hydrogen atoms bonded to carbon than carbohydrates and proteins. − C H 2 − is a typical carbon hydrogen bond in lipids. When oxidized, this carbon releases 6 electrons that it can donate to reduce NAD and FAD during the electron transport chain of cellular respiration.H − C − O H  is a typical C-H bond in carbohydrates. When oxidized, this bond only releases 4 electrons. Moreover, a higher concentration of proton is generated by breakage of the CH bond in lipids. This would generate a steeper proton gradient required for running the enzyme ATP synthase. As more protons cross the mitochondrial membrane, the ATP synthase phosphorylates more ADP molecules resulting in a greater production of ATP.

The answer is c) organisms that are sensitive to changes in temperature would die.