Answer: Option E) polar
Amino acid-derived and peptide hormones are unable to diffuse across a cell membrane because they are polar
Explanation:
Amino acid-derived and peptide hormones such as serotonin, epinephrine, dopamine etc, are unable to diffuse across a cell membrane because they consist of several repeating units of amino acids with positively charged or negatively charged side chains.
Thus, the side chains make these hormones water-loving (hydrophilic), and impassable to the hydrophobic layer of the cell membrane.
