Some of the lipid groups appear similar, but changing a few components significantly alters their biological properties. identify the similarities and differences between glycerophospholipid and sphingolipid structures.

In cells there are two classes of phospholipids, glycerophospholipids and sphingophospholipids.

Glycerophospholipids have two fatty acids attached to a glycerol molecule, since the third hydroxyl group of this alcohol is esterified with a phosphate, in turn attached to a second alcohol. The combination of glycerol with two fatty acids and phosphate results in a molecule called phosphatidic acid, which forms the basic structure of glycerophospholipids.

Sphingophospholipids contain ceramide, which is a molecule formed by the union of two fatty acids with a serine (which replaces the glycerol present in glycerophospholipids). The union of a serine with one of the fatty acids forms the amino alcohol called sphingosine or sphingol. Serine is formed by the aggregation of a fatty acid with sphingosine. The sphingophospholipid in the cells is sphingomyelin, originated from the union of ceramide with phosphorylcholine.

Despite the differences. both exhibit two large non-polar hydrophobic tails (two fatty acids) and a polar hydrophilic head comprising glycerol, phosphate and the second alcohol. For such characteristics phospholipids are amphipathic molecules.

The first organic molecules were likely made when lightning caused a chemical reaction in our atmosphere. That early atmosphere was composed of many gases including ammonia, methane, water vapor, and carbon dioxide.