lipids

Steroids

characteristic 17-carbon ring system

The biosynthesis of all steroid hormones starts from

cholesterol

fatty acids

Carboxylic acid with a long hydrocarbon chains

If the hydrocarbon chain contains only C−C single bonds, the faƩy acid is

saturated

If the chain contains at least one C=C double bond, the fatty acid is

unsaturated

when a fatty acid is mixed with a base

the carboxylic acid ionizes and H20 is a byproduct

what is soap

salt of a fatty acid

partial hydrogenation

a deficient amount of H2 and/or a weaker hydrogenation
catalyst is used resulting in only some of the double bonds being hydrogenated.

• The result will be a mixture of products: cis-unsaturated (highest percent),
saturated fatty acid (smallest percent) and trans-unsaturated (small percent)

lowest to highest melting point fatty acids

polyunsaturated < cis-monounsaturated < trans-monounsaturated < saturated

waxes

ester made from the condensation between a long chain alcohol and a fatty acid

saponification of a wax

breaking apart a wax back to fatty acid and alcohol using strong base

• the carboxylic acid will ionize

triglycerides

(fats and oils) are triesters made from the condensation reaction
of glycerol (a tri-alcohol) with three fatty acids (which may or may not all be the same).

glycerol

triglycerides wit strong base

will separate glycerol backbone and ionize carboxylic acid of fatty acids

phospholipids

• long nonpolar
  hydrophobic chains and a hydrophilic ionized phosphate group

• contain an ionized phosphate group (PO4)

• usually bonded to an amino
  alcohol such as ethanolamine, choline or serine via a phosphoester bond.
  

phosphate and ionized ethanolamine

phosphate and ionized choline

phosphate and ionized serine

Glycerophospholipids

glycerol backbone, 2 esters from fatty acids, and ionized phosphate, and amino alcohol

Sphingomyelin

another type of phospholipid found in animal cell membranes, especially
around the membranous myelin sheath that surround nerve cell axons

• one fatty acid, sphingosine + amino alcohol + phosphate

what does the green represent

sphingosine backbone