The smell that first hits you when you open a bag of popcorn is perhaps one of the most satisfying, but it may be harmful to your health.
Chemical Nature of Hormones. Chemically, hormones may be classified as either proteins or steroids. All of the hormones in the human body, except the sex hormones and those from the adrenal cortex, are proteins or protein derivatives.ome endocrine glands secrete hormones in response to other hormones. The hormones that cause secretion of other hormones are called tropic hormones. A hormone from gland A causes gland B to secrete its hormone.
Lipophilic Hormones with Intracellular Receptors. Many lipid-soluble hormones diffuse across the plasma membrane and interact with receptors in the cytosol or nucleus. The resulting hormone-receptor complexes bind to transcription-control regions in DNA thereby affecting expression of specific genes (see Figure 20-2a).Hormones of this type include the steroids (e.g., cortisol, progesterone, estradiol, and testosterone), thyroxine, and retinoic acid (see Figure 10-65).he resulting hormone-receptor complexes bind to transcription-control regions in DNA thereby affecting expression of specific genes (see Figure 20-2a). Hormones of this type include the steroids (e.g., cortisol, progesterone, estradiol, and testosterone), thyroxine, and retinoic acid (see Figure 10-65).