Lipids and MembranesEdit
Membranes serve as the boundary for the cell, separating the inside of the cell from the exterior environment; they exclude toxins and sequester nutrients. They are composed of lipids, proteins and a variety of small molecules. The primary cell membrane is the plasma membrane.
Fatty acids have a polar head made up of oxygen atoms and a non-polar tail comprised of hydrocarbons. The shape of the chain depends on the number of double bonds. Saturated fats have no double bonds and unsaturated fats have 1 or more double bonds. The presence of double bonds in the non-polar tail increases fluidity when the chains are packing together.
Properties of Fatty AcidsEdit
Fatty acids with no double bonds pack tightly together, are less fluid-like, have a high melting point and may be solid at body temperature. Unsaturated fatty acids with one double bond are called monounsaturated, Unsaturated fatty acids with more than one double bond are called polyunsaturated. The Cis double bond predominates. Trans double bonds behave more like saturated chains and are less fluid when packed.
Essential Fatty AcidsEdit
- Linoleic acid
- Linolinic Acid