複選題
23. Translation defines the cellular proteome； which statement is correct?
(A) Translational control has nothing to do with mRNAs.
(B) The Cer4-Not complex affects mRNA translatability.
(C) The elongation of translation is a uniform process.
(D)Ribosome pausing increases translation efficiency.
(E) The regulation of translation is independent of cell status and environment.

19.The DNA-binding proteins that recognize and accurately initiate transcription at specific eukaryotic promo called: (A) enhancers (B) transcription factors (C) response elements (D) chromatin-remodeling complexes (E) All are true

20. Functional DNA is not found in: (A) bacterial nucleoids(B)chloroplasts(C)lysosomes(D) mitochondria(E)nuclei

21.The cell metabolism is tightly connected to the regulation of gene expression. The lac operon (lactose operon) is an example. Which statement below regarding the lac operon is correct? (A)There are lacZ, lacY and lacA genes in lac operon and they are transcribed ind(B)RNA polymerase binds to operator in the absence of lactose. (C) The operon is controlled by negative and positive transcription factors. (D) In the presence of lactose, the lac repressor encoded by the lacI gene is not expressed for ope ron activation.(E) In the presence of high concentration glucose, the catabolite activator.protein (CAP) is activated to increase Lac Zexpression.

22.The 2019 Nobel Prize in Physiology or Medicine was awarded to three scientists for discovering hypoxia-ind transcription factor that regulates gene expression in response to decreases in cellular oxygenation. Unde n, HIF1a-HIF 1β heterodimer bonds to target genes' HRE (hypoxia-tesponse element), leading to gen ygen condition, HIF 1a is hydroxylated in two ( residues and recruits E3 () ligase for protein deg the three blanks? (A) Activation, proline, ubiquitin. (B) Inhibition, proline, ubiquitin. (C) Activation, histidine, ubiquitin. (D) Inhibition, histidine, SUMO. (E) Activation, proline, SUMO.

24.Consider the canonical nuclear localization sequence (cNLS) mediated protein transport mechanism； which statement is correct? (A) The cargo-carrier import complex is assembled in the nucleus. (B) The cargo protein utilizes its cNLS direct contact with the importinβ. (C) The RanGDP protein is more concentrated within the cytoplasm than the nucleus in preparation for cargo protein transport. (D) The RanGDP protein is essential to export the importin from the nucleus. (E) The cargo protein translocation is through the nuclear pore complex in the endoplasmic reticulum.

25. Vesicular transport describes vesicles bud off from one compartment and fuse with another. Most transport vesicles form from specialized, coated regions of membranes. They therefore bud off as coated vesicles. Which statement(s) is correct regarding coated vesicles?(1) Clathrin-coated vesicles mediate transport originating from the Golgi apparatus, endosome, and the plasma membrane. (2) COPI-coated vesicles contribute to the ER-to-Golgi transport, comprising large protein subcomplexes that are made of seven different protein subunits.(3) The retromer complex has been shown to mediate retrieval of various transmembrane receptors, such as the cation- independent mannose 6-phosphate receptor. (A) (3) only (B) (I) and (2) (C) (2) and (3) (D) (1) and (3) (E) All of above are correct.

26. Which of the following statement(s) is cotrect regarding to protein endocytosis or exocytosis? (1)Clathrin-mediated endocytosis involves cargo recognition and coat assembly, followed by membrane inv finally pinching off to deform membranes.(2) Proteins being internalized move to the lysosome and recycling endosome for protein degradation and reuse, respectively.(3) Neurotransmitters are typically released from synaptic vesicles into the synaptic clett via exocytosis, which is the fusion of vesicles with the plasma membrane. (A) (1) and (2) (B) (2) and (3) (C) (1) and (3) (D) (3) only (E) All of above are correct.

27. Which of the following statements regarding stem cells (SCs) is correct?(1) A stem cell can divide to one copy of itself and to one differentiated cell.(2) The pluripotent SCs showed higher differentiation potency than the totipotent and multipotent SCs.(3) Stem cells could be used to test new drug. (A) (1) (B) (2) (C) (3) (D) (1) and (3) (E) (2) and (3)

28. Which of the following statement regarding neurotransmitter is correct? (1) A neurotransmitter can be re-uptaken back to the presynaptic neuron. (2) Gamma aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the brain. (3) The role of a neurotransmitter agonist is to mimic or enhance the effects of specific neurotransmitters. (A) (1) and (2) (B) (1) and (3) (C) (2) and (3) (D) all of the above (E) none of the above

29. Which of the following statement about membrane potential and action potential propagation is NOT correct? (A) The resting membrane potential of animal neurons depend largely on non-gated K+ channels. (B) The resting potential of a typical neuron is -30 mV. (C) During an action potential, opening of voltage-gated Na+ channels happens first (D) Repolarization during the refractory period is largely due to opening of voltage-gated K+ channels. (E) All above are incorrect.