Final answer:
Tay-Sachs Disease is characterized by the harmful build-up of sphingolipids in brain and nerve cells due to enzyme deficiency.
Step-by-step explanation:
In Tay-Sachs Disease, the build-up of certain lipids known as sphingolipids gradually destroys brain and nerve function. This accumulation is due to a malfunction in an organelle responsible for breaking down these lipids. In healthy cells, sphingolipids are important constituents of the myelin sheath that surrounds the axon of a nerve cell but in Tay-Sachs, the enzyme needed to break down sphingolipids is missing or dysfunctional, leading to their harmful build-up.