Cells are so small so the surface area and volume of them can be proportional to each other. This helps with the efficiency of the cell's absorption and waste expulsion processes. Also by the cell's smallness, communication from the nucleus to other organelles is fast and the cell can be regulated while the conditions for diffusion are still ideal.Its because they need to be able to diffuse through materials easily. Also, materials inside and outside of the cell need to easily pass through the cell membrane, which makes it harder and slower for the materials to pass through the cell membrane.
the answer is ATP. ATP is the bi- product that cells can easily absorb 4 energy. the body digests the glucose first, whatever is left after that is ATP..
