EVERYDAY SCIENCE

Detailed explanation-1: -Hydrophilic hormones are poorly lipid soluble and cannot pass through membranes – they bind with receptors on the outer cell membrane surface. Lipophilic hormones pass easily through the phospholipid layer of the target cell membrane – they bind with receptors inside.

Detailed explanation-2: -Lipid-insoluble hormones bind to receptors on the outer surface of the plasma membrane, via plasma membrane hormone receptors. Unlike steroid hormones, lipid-insoluble hormones do not directly affect the target cell because they cannot enter the cell and act directly on DNA.

Detailed explanation-3: -Nonpolar hormones can pass through the nonpolar phospholipid bilayer of the cell membrane, while polar hormones cannot pass through the cell membrane and must bind to receptors on the surface of the cell.

Detailed explanation-4: -Steroid hormones are generally thought to pass easily across a plasma membrane into a cell, interacting once inside with soluble nuclear receptors, but recent experiments have demonstrated the importance of membrane-bound receptors in mediating the activity and the metabolism of steroid hormones.

Detailed explanation-5: -Amino acid derived hormones and polypeptide hormones are not lipid-derived (lipid-soluble) and therefore cannot diffuse through the plasma membrane of cells.