Complex-lipid metabolism

What you will learn

• Relate substrates, enzymes and CDP routes to the glycerophospholipids they produce.
• Describe synthesis of ceramide, sphingomyelin and glycosphingolipids.
• Recognize sphingolipidoses and associate each disease with its enzyme and accumulated lipid.
• Predict products released by phospholipases A1, A2, B, C and D.

Course outline

1. Two backbones organizing complex lipids

   Distinguish glycerophospholipids and sphingolipids before following their synthesis, diversification and degradation.

   18 min

2. Building the phosphatidic-acid precursor

   Separately follow the glycerol-3-phosphate and DHAP routes to their common intermediate and then phosphatidic acid.

   32 min

3. The CDP-diacylglycerol pathway

   Activate phosphatidate with CTP, then separately form phosphatidylinositol, phosphatidylglycerol and cardiolipin.

   30 min

4. The CDP-alcohol pathway and nitrogenous phospholipids

   Activate choline and ethanolamine separately, transfer them to diacylglycerol, then form phosphatidylserine or phosphatidylcholine by conversion.

   38 min

5. Building ceramide

   Condensation, reduction, N-acylation and desaturation convert palmitoyl-CoA and serine into the sphingolipid crossroads.

   30 min

6. Forming sphingomyelin, cerebrosides and gangliosides

   Add phosphocholine or activated sugars to ceramide to create distinct families.

   25 min

7. Sphingolipidoses: one lysosomal block, one precise accumulation

   Independently connect each deficient enzyme with the accumulating sphingolipid, then detail Tay–Sachs and Niemann–Pick.

   45 min

8. Phospholipases: one enzyme for each bond

   Locate phospholipases, then independently distinguish A1, A2, B, C and D cleavages and their products.

   34 min