In terms of macromolecules, needed and utilized by organisms to carry out essential metabolic chemical reactions and for maintaining structure would be Lipids.
Lipid based molecules or Fats tend to store the most energy, as breaking chemical bonds connecting fatty acid chains of long hydrocarbons releases quite a bit of energy.
The answer is d. semi permeable nature of the membrane
i think the answer is D) but you should get someone else to confirm this.
cell membrane forms the surface of a cell to protect it from the outside world.
