Pan-African flag - History. 1  The flag was created in 1920 by members of UNIA in response to the enormously popular 1900 coon song Every Race Has a Flag but the Coon. [4] which has been cited as one of the three songs that firmly established the term coon in the American vocabulary.
A ligand is any molecule that binds to a specific site on a protein or other molecule. In this case, the estrogen hormone 17-beta-estradiol is the ligand, and the estrogen receptor is the protein. Binding turns on, or activates, a hormone receptor.
Hormones, though, only bind to certain, compatible receptor types. Thyroid hormones and each steroid hormone group-the estrogens, androgens, progestins, glucocorticoids (stress hormones), and mineralocorticoids (water and ion-regulating hormones) - have a matching hormone receptor type.hether a hormone binds to a receptor inside or outside a cell depends on the chemical nature of the hormone and its compatibility with the cellâs fatty outer membrane. The membraneâs fat layers impede water-friendly hormones from passing through but allow fat-derived hormones to readily enter the cell.