How do steroid hormones differ from polypeptide hormones and most amino-acid-derived hormones? a. Steroid hormones are lipid soluble and cross plasma membranes readily. b. Polypeptide and amino-acid-derived hormones are longer lived in the bloodstream and thus exert greater signal amplification. c. Polypeptide hormones are the most structurally complex and induce permanent changes in target cells. d. Only steroid hormones bind to receptors in the plasma membrane.