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.
Answer:
Osmosis is the process of having water pass from a low concentration medium to a high concentration one, given that the barrier (membrane) is semi-permeable.
Explanation
Cells encounter osmosis due to their semi-permeable membranes. Water can flow past cell membranes. A given cell placed into distilled water will have some water flow into it, causing it to burst. A given cell placed in a very concentrated water will have some water flow out of it, causing it to shrivel. A given cell placed in a solution with the same concentration of minerals as the cell will have an equilibrium of water flowing in and out. This is the case of IV (Intravenous therapy) when we want to deliver substances into a human blood. We want to make sure the liquid delivered is as concentrated as the blood to avoid cell shriveling or bursting.
This picture above sums up the 3 cases cells could face in a solution.
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