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.
Whether 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.
1 Ion channel-linked receptors bind a ligand and open a channel through the membrane that allows specific ions to pass through.  G-protein-linked receptors bind a ligand and activate a membrane protein called a G-protein, which then interacts with either an ion channel or an enzyme in the membrane.