11.Signaling at synapses is usually terminated by
(A) calcium influx.
(B) potassium influx.
(C) inhibitory neurotransmitters.
(D) degradation or reuptake of neurotransmitters.
(E) none of the above.

7.The sodium-potassium pump establishes concentration gradients (A) of higher sodium concentrations inside the cell and higher potassium concentrations outside the cell. (B) of sodium and potassium but the area of their concentrations depends on the needs of the cell. (C) of higher potassium concentrations inside the cell and higher sodium concentrations outside the cell. (D) of ATP inside the cell where it is needed. (E) by pumping sodium outside the cell and potassium is cotransported out as well.

8.Which of the following component(s) is NOT required for those proteins to be internalized during endocytosis? (A) cargo adaptor (B) coat protein (C) GTPase (D) translocon (E) All of above are used in the secretory pathway

9. Which of the following pathway(s) is NOT the correct description for secretory proteins during protein transport? (A) Secretory proteins move to the plasma membrane for protein expression. (B) Trans-Golgi network is thought to be the sorting hub for secretory proteins. (C) Secretory proteins can be recycled back to ER using the tyrosine-based sorting motif. (D) Secretory proteins move to ER by cotranslational transport machinery in mammalian cells. (E) All of above are correct.

10. Polymerization of collagen into large collagen fibers occurs (A) in the endoplasmic reticulum. (B) in the Golgi complex. (C) in secretory vesicles. (D) extracellularly. (E) none of the above.

12. Which repair is considered as an error-free mechanism? (A) Homologous recombination (B) Non-homologous end-joining (C) Microhomology-mediated end-joining (D) Single strand annealing (E) Transcription-coupled DNA repair

複選題13. Which one participates in the adaptive immune response? (A) B cell (B) NK cell (C) T cell (D) Neutrophils (E) macrophages

14.Apoptosis differs from necrosis in that necrosis__________. (A) requires the reception of an extracellular signal. (B) causes DNA to fragment. (C) causes cells to swell and burst, whereas apoptotic cells shrink and condense. (D) involves a caspase cascade. (E) all of the above

15. The following methods can separate proteins based on their mass except? (A) centrifugation (B) ion exchange chromatography (C) SDS polyacrylamide gel electrophoresis (D) gel filtration chromatography (E) native polyacrylamide gel electrophoresis

16. While examining the crystal structure of a membrane protein, you find several phospholipid molecules bound to the protein. You know that these lipids .(1) are thought to help stabilize many membrane proteins.(2) may enhance the crystallization of the bound membrane proteins.(3) interact specifically with the protein.(4) can have head groups of various sizes and charges depending on the protein. (A) 1,2 and 3 (B) 2,3 and 4 (C) 1, 3 and 4 (D) 1 only (E) All

17. Many cells store lipids in droplets of varying sizes. These droplets ... (A) have mostly protein-free bilayer membranes. (B) are composed primarily of charged amphiphilic lipids. (C) are produced by and released from the Golgi apparatus. (D) are enclosed by a phospholipid monolayer (instead of a bilayer). (E) mostly store cholesterol and phospholipids.