True or False? True False
1. Proteins rapidly pass artificial membrane (liposome). ————————————————————————————– ( ) ( )
2. Amphiphatic detergent such as SDS spontaneously forms bilayer in water. ———————————————————— ( ) ( )
3. Cholesterol does have a hydrophilic head and hydrophobic tail. ————————————————————————- ( ) ( )
4. Fat molecules are one of the major components of the plasma membrane. ————————————————————- ( ) ( )
5. Phospholipid molecules such as phosphatidylcholine spontaneously form bilayer. —————————————————- ( ) ( )
6. Flippase facilitates lateral movement of phospholipids within the plane of the membrane. —————————————– ( ) ( )
7. Glycolipids make bilayer less permeable to small water soluble molecules. ———————————————————– ( ) ( )
8. Membrane inner leaflet is enriched with phosphatidylcholine, Sphingomyelin, and Glycolipid. ———————————– ( ) ( )
9. Plasma membrane proteins can have an enzyme activity. ——————————————————————————– ( ) ( )
10. A single pass membrane protein must have an amphiphatic alpha helix. ————————————————————– ( ) ( )
11. Plasma membrane proteins can be linked to a lipid molecule at the outer leaflet of the plasma membrane. ——————— ( ) ( )
12. The lateral motility of membrane proteins can be restricted by tight junctions. —————————————————— ( ) ( )
13. Channel proteins have specific binding sites for ions and thus slower than carrier proteins. ————————————— ( ) ( )
14. An antiport would function as a symport if its orientation in the membrane were reversed. ————————————— ( ) ( )
15. A transmembrane pore can be formed by multiple amphipathic alpha helices. —————————————– ( ) ( )
16. Porin proteins form water-filled channels in the outer membrane of a bacterium and are mostly composed of beta sheets. —- ( ) ( )
17. Glucose uniporters localize at the apical side of the intestinal epithelium. ———————————————————— ( ) ( )
18. GAP junction is a selective pore for anions. ———————————————————————————————– ( ) ( )
19. A voltage-gated Na+ channel adopts only two conformation states: open and closed. ———————————————– ( ) ( )
20. Voltage gated K+ channel opens faster than the Voltage gated Na+ channels. ——————————————————– ( ) ( )
21. Opening of chloride channel at the synapse will help to fire an action potential. —————————————————— ( ) ( )
22. The nuclear pore complex forms a gate through which molecules pass the nucleus uni-directionally. ——————– ( ) ( )
23. A completely folded protein is imported into a mitochondrion through a large non-selective pore. ——————————— ( ) ( )
24. ER signal sequence contains multiple lysine and arginine residues. ———————————————————————- ( ) ( )
25. The plasma membrane is a sorting station of inward endocytic pathway. —————————————————————- ( ) ( )
26. The trans Golgi functions as a sorting station of outward secretory pathway. ———————————————————– ( ) ( )
27. Vesicles budding from ER are coated with Clathrin. —————————————————————————————- ( ) ( )
28. RabGTPases and tethering proteins are the major specificity determinant of vesicle transport system. ————————– ( ) ( )
29. v-SNARE proteins are one of the tethering proteins. ———————————————————————————— ( ) ( )
30. In secretory cells, the constitutive and regulatory pathways of exocytosis diverge at the cis Golgi network. —————— ( ) ( )
31. Many proteins are posttranslationally glycosylated at tyrosine residues in the ER. ————————————————- ( ) ( )
32. Cells import LDL molecules exclusively through pinocytosis. ————————————————————————- ( ) ( )
33. Cells recycle LDL receptors from lysosome to the plasma membrane. —————————————————————– ( ) ( )
34. Phagosomes fuse with late endosome. —————————————————————————————————— ( ) ( )
35. Small vesicles from ER near the plasma membrane can fuse with the plasma membrane upon bypassing Golgi apparatus. — ( ) ( )
36. If a Sec mutant showed an accumulation of newly synthesized proteins at ER,
then the Sec gene is likely a component of vesicle-budding machinery of trans-Golgi network. ———————————— ( ) ( )
37. A signal recognition particle is a single pass trans-membrane protein of the ER membrane. —————————————- ( ) ( )
38. Typical animals cells display higher levels of intracellular sodium than extracellular compartments. —————————— ( ) ( )
39. Typical animals cells display higher levels of intracellular chloride than extracellular compartments. —————————– ( ) ( )
40. The Na-K Pump is a GTPase that can adopt active and inactive conformational states. ———————————————– ( ) ( )