What is the functional group for lipids?

Answer 1

Hydroxyl GroupThe hydroxyl group is the smallest portion of the cholesterol molecule consisting of just one oxygen atom bound to one hydrogen atom. The electronegativity of the oxygen atom gives the molecule a polar structure. The shared electrons in the bond between hydrogen and oxygen surround both nuclei in a cloud, but they favor the oxygen side, resulting in a slightly negative charge on one end and a slightly positive charge on the other. The presences of the hydroxyl group makes cholesterol an alcohol, and it is also the only portion of cholesterol that, on its own, is water soluble. Steroid NucleusThe bulk of the cholesterol molecule is made up of a central region of hydrogen and carbon atoms bound in rings. This nucleus contains four hydrocarbon rings, three with six carbon atoms bound to two hydrogen atoms each and one with five carbon atoms bound to two hydrogen atoms each. The non-polar bond between hydrogen and carbon means the shared electron cloud between them is evenly distributed resulting in no positive or negative poles. Non-polar molecules are fat-soluble because, even though the bonds between the atoms are weak and they can be easily broken, water is polar, and its bonds are strong. Hydrogen and carbon won't break apart unless they have somewhere to go, and it is not strong enough to attach to water molecules, but it is strong enough to bond with other hydrocarbons. Hydrocarbon TailHydrocarbons are structures that contain one or more hydrogen atoms bound to one or more carbon atoms. Hydrocarbons in the form of fossil fuels power our cars, trucks and airplanes as well as heat our homes. The non-polar structure of the hydrocarbon bond makes it insoluble in water leading to the axiom, "oil and water do not mix." The presence of the hydrocarbon tail in the cholesterol molecule makes it fat soluble only, despite the presence of the hydroxyl group, so cholesterol overall is just insoluble enough to maintain its structure in the blood. This is why cholesterol is transported through the body by lipids, another non-polar molecule.

Answer 2

Carboxyl