Cardiolipin is made up of two molecules of phosphatidic acid combined to a molecule of glycerol. It is the only phosphoglyceride that is antigenic in nature. It is synthesised by phosphotidylglycerol. Phosphatidic acid is a precursor of phosphptidylglycerol, which, in turn, gives rise to cardiolipin in mitochondria.
Ceramide is synthesised in endoplasmic reticulum. First, the amino acid serine following activation by combination with pyridoxal phosphate combines with palmitoyl-CoA to form 3-keto sphingosine. This is converted to dihydrosphingosine in a reductive step utilising NADPH. Dihydro ceramide is formed by combination with acyl-CoA, followed by desaturation to form ceramide.
The structure of cerebrosides is somewhat similar to that of phosphosphingosides. They contain a high molecular weight fatty acid, sphingosine, and either galactose or glucose instead of choline but no phosphoric acid. They have no electric charges since their polar groups are neutral. In general properties, they resemble sphingomyelin. The sphingosine – fatty acid portion…
Cerebrosides are important constituents of brain, where they amount to 8% of the solid matter. These may also occur in tissues other than brain. Since the head group consists of one or more sugar units, cerebrosides are often called glycosphingosides. In Gaucher disease, the cerebrosides appear in relatively large amount in the liver and spleen.…
Cerebrosides are also known as galactose lipids because of their galactose content. They have no phosphoric acid group. They are compounds of fatty acid of high molecular weight, sphingosine and galactose. Four cerebrosides have been identified according to their fatty acid component. They are as follows:
Phospholipids are degraded by phospholipase, which cleaves phosphodiester bonds. These enzymes are found in mammalian tissues, pancreatic juice, and snake venom and some toxins. Certain pathogenic bacteria produce phospholipase, which helps in the spread of infection by dissolving cell membranes.