These proteins allow substances to enter that wouldn't be able to otherwise. Only small hydrophobic substances can enter cells. However, these proteins aid crucial substsances in entering the cell.<span />
Answer: I believe it is D, the Nervous System.
Explanation:
Answer:facilitated diffusion
Explanation: facilitated diffusion us the carrier-mediated Transport of large molecules across the cell membrane using Transport proteins found in the cell membrane.such molecules include glucose,amino acids and ions.the passage across the membrane is from higher concentration to lower concentration