BIO 2200 H?STEN 2003 Sp?rsm?l ¡­

BIO 2200 H?STEN 2003

Sp?rsm?l til kollokviene 22. september 2003-09-15

1. What are the roles/functions of the vacuolar proton pump in the endocytic and the secretory/biosynthetic pathways?

2. Explain/describe ?The unfolded protein response in yeast? (Fig 12-56).

3. What happens to lysosomal hydrolases in the Golgi apparatus, and how are they transported to lysosomes?

4. Is it conceivable that a lysosomal enzyme may be brought to lysosomes without being bound to the mannose-6-phosphate receptor? Explain your answer!

5. How do lysosomal enzymes receive their substrates?

6. (True/false) Any particle that is bound to the surface of a phagocyte will be ingested by phagocytosis. Explain your answer. Do you know any receptors that mediate phagocytosis?

7. In cells (fibroblasts) from a patient with severe familial hypercholesterolemia the surface binding of LDL (low density lipoprotein) is nearly normal, but the lipoprotein is not internalized. Do you have any explanations?

8. Describe the endocytic pathways followed by LDL, EGF and transferrin.

9. What are the main functions of phagocytosis?

10. What are the functions of multivesicular bodies? How is the epidermal growth factor receptor degraded? What is the role of ubiquitination in endocytosis?