Glycolipids
Start with the big picture
Glycolipids are concentrated in the outer leaflet of plasma membranes, where their carbohydrate groups face the extracellular space; they are especially abundant in brain and myelin. They participate in cell-cell recognition, signal transduction, immune modulation, and interactions with toxins and viruses. Neutral forms include cerebrosides and globosides, while acidic forms include sulfatides and gangliosides. Glycolipids are assembled in the ER and Golgi using sugar donors and glycosyl-transferases, then degraded stepwise in lysosomes. Defects in specific degradative enzymes can cause sphingolipidoses. Examples include GM1 as a cholera-toxin receptor and GM2 accumulation in Tay-Sachs disease. Their antigenicity also contributes to blood-group testing and some autoimmune neuropathies.
What you'll learn
- Describe the structural features that distinguish glycolipids from phospholipids.
- Explain glycolipid membrane location and the orientation of their carbohydrate groups.
- Classify glycolipids as neutral or acidic and identify representative types.
- Outline glycolipid biosynthesis and lysosomal degradation.
- Relate selected glycolipids and enzyme defects to clinical conditions.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
