複選題

8. Which of the following statements regarding proteasome degradation pathway are correct?
(A) Proteins targeted for degradation are usually mono-ubiquitylated.
(B) Ubiquitin is transferred to substrate proteins by the so-called E3 enzymes.
(C) This pathway is ATP-dependent.
(D) Inhibition of proteasome degradation pathway may lead to cell cycle arrest.
(E) This pathway also involves in antigen presentation.

複選題4. Which ligands or receptors are involved in the second messengers in cells? (A) IGF receptor (B) cholecalciferol (C) androgen receptor (D) leukotriene receptor (E) acetylcholine receptor

複選題5. Which of the following descriptions regarding double-stranded DNA molecules are correct? (A) They can exist as A-, B-, or Z-form. (B) The two strands are antiparallel and complmentary with each other. (C) An AT-rich DNA sequence (that is, a sequence contains more AT base pairs) is usually more stable than a GC-rich sequence. (D) The stacking interactions between neighboring base pairs provide stability to a DNA molecule. (E) The major groove of B-form DNA is wider than the minor groove.

複選題6. Inhibition of DNA topoisomerases may lead to which of the following events? (A) inhibition of replication (B) apoptosis (C) inhibition of transcription (D) DNA damages (E) cell cycle arrest

複選題7. Which of the following molecules may influence the structures of RNA molecules? (A) carbon monoxide (CO) (B) polyamines (C) magnesium ion (D) histones (E) helicases

複選題9. What factor(s) can make tumor suppressor RB inactive? (A) CDK2 (B) CDK4 (C) Cdc25 phosphatase (D) SV40 T antigen (E) HIN1 hemagglutinin.

10. Which-following protein(s) can shuttle between cytoplasm and nucleus? (A) Erk1/2 (B) Akt (C) STAT3 (D) insulin receptor (E) Src.

複選題11. Which following statement(s) is/are correct? (A) Protein glycosylation occurs immediately after protein synthesis is complete. (B) Protein glycosylation happens during the process of protein synthesis. (C) Protein glycosylation begins in endoplasmic reticulum. (D) Protein glycosylation occurs only after the protein is transported to Golgi. (E) A given protein can have different glycosylation modifications in different types of cells.

複選題12. What following alteration(s) will let an oncogene become oncogenic? (A) gene amplification (B) protein overexpression (C) CpG island methylation (D) ubiquitination (E) loss of function on a cognate inhibitor which is specific for the protein translated from the oncogene.

13. DNA pyrosequencing is a method that reads DNA sequence based on the amount of pyrophosphate generated by the DNA polymerase. For each sequencing cycle, one single triphosphate nucleotide (A) GCTAGCT (B) GCAGCT (C) GCTAGGCCT (D) GCAGGCCT (E) CGTCCGGA

14. Which of the following statements about DNA agarose electrophoresis is TRUE? (A) DNA carries negative charges and run to anode (B) Large DNA carries more negatives and run faster than small DNA (C) Large DNA run slower because it is heavier than small DNA (D) Large DNA run slower because it faces a greater resistance (E) Low percentage agarose gel provides better resolution for small DNA