Tay-Sachs Disease (Lysosome)

Question 1

Clinical findings = normal at birth; abnormal accumulation of lipids in some cells; Gradual onset of retarded neurological development; Increase head size

Answer 1

Brain and macular degeneration; Seizures, convulsions, death by 2 years; Brain weight increased by 50%; Neurons have lipid-containing lysosomes;
Very rare

Question 2

What are newly formed lysosomes called?

Are they active?

Answer 2

Primary lysosomes are NOT active until they merge w/ an endosome, which is then a secondary lysosome (active)

Question 3

What happens to membrane receptors after primary lysosome binds with endosome?

Answer 3

CURL; Compartment of Uncoupling of Receptor and Ligand

Question 4

What are the 3 major, specific functions of lysosomes?

Answer 4

Autophagy, Heterophagy, and “External Operations”

Question 5

What is Autophagy?

What is Heterophagy?

Answer 5

Auto = Self-digestion
Hetero = Digestion of foreign materials

Question 6

What does ‘Hex A’ hexosaminidase A do?

If missing, what happens?

Answer 6

breaks down gangliosides (key elements in myelin)

If missing, breakdown doesn’t happen and lipid accumulates