Practice Problems Solutions 1. One of the esters is a phosphate ester, so this lipid is a phospholipid. Each has a hydrophilic head group and a long hydrophobic tail. Each removes grease by forming micelles. The metal cations are different.
Steroids are fairly flat due to the fairly flat nature of a cyclohexane chair conformation.
For the conformation to change, it would have to assume a diaxial conformation. The diaxial conformation is several kcal per mole higher in energy than the diequatorial conformation, so the equilibrium constant greatly favors the diequatorial side, and the tetracyclic portion of the molecule has essentially only one conformation. Aid in digestion by emulsifying fats. Signal molecules that control various aspects of sexuality. Regulate electrolyte levels.