83. Which statement about the chain elongation of vertebrate fatty acids is NOT true?
(A) It occurs on the endoplasmic reticulum.
(B) It utilizes malonyl-CoA as a substrate.
(C) It elongates palmitoyl-CoA to stearoyl-CoA.
(D) It gives a saturated fatty acyl-CoA two carbons longer than the original substrate.
(E) It occurs in the cytoplasm.

79. Which statement about energy metabolism in patients with type I diabetes mellitus and poor blood glucose control is NOT true? (A) Ketone bodies are mainly derived from the metabolism of glucose-produced acetyl-CoA. (B) Ketone bodies can replace glucose as a cellular energy source. (C) Intermediate products of the Krebs cycle, such as oxaloacetate, are used in gluconeogenesis, leading to an increase in blood glucose. (D) Due to the lack of oxaloacetate, acetyl-CoA cannot enter the Krebs cycle, resulting in its conversion into ketone bodies. (E) Fatty acids are converted into ketone bodies as an alternative energy source in the absence of glucose.

80. A young boy is unusually tall and presents with joint laxity and retinal detachment. Examination reveals a mutation in the tripeptide repeat of type II collagen, affecting its quaternary structure. Which amino acid is most likely affected by this mutation? (A) hydroxylysine (B) hydroxyproline (C) glycine (D) tryptophan (E) proline

複選題81. How is DNA recombination achieved during meiosis? (A) Double-strand break recombination (B) Single-strand break recombination (C) Telomere recombination (D) Centromere recombination (E) Homologous recombination

82. What is the main pharmacological action of benzoate and phenylbutyrate, which are used to treat urea cycle disorders? (A) It provides intermediates required for the urea cycle to enhance the efficiency of the entire urea cycle. (B) It acts as allosteric activators of carbamoyl phosphate synthase I to enhance the efficiency of the urea cycle. (C) Their metabolites combine with glycine and glutamine, respectively, to form derivatives that are excreted, reducing the burden on the urea cycle. (D) It promotes the synthesis of arginine to prevent arginine deficiency. (E) It increases the activity of ornithine transcarbamylase to facilitate urea synthesis.

84. P53 ______. (A) belongs to oncogene (B) regulates the activity of E2F transcription factor (C) cannot interact with DNA (D) repairs DNA damage directly (E) acts as a transcription factor to regulate cell cycle

85. Retinoid acid ______. (A) can be converted to retinal in the body (B) participates in the synthesis of β-carotene (C) combines with nuclear receptor that binds to specific DNA sequence (D) can replace vitamin A in the diet (E) acts as a chaperone at post-translational modification

86. What type of DNA will be formed if a DNA segment has one all-pyrimidine strand and one allpurine strand? (A) A-DNA formation (B) B-DNA formation (C) G-Quadruplexes (D) H-DNA formation (E) Z-DNA formation

87. How many of the following molecules act as second messengers?GTP； calcium ion； cGMP； cAMP； inositol-1,4,5-triphosphate； diacylglycerol； ATP； insulin (A) 8 (B) 7 (C) 6 (D) 5 (E) 4

88. Which of the following endogenous DNA-damaging reactions occurs most frequently in cells? (A) depurination (B) ROS oxidation (C) methylation (D) deamination (E) depyrimidination

89. How many pairs in the following are TRUE?- Iron-sulfur protein– electron flow from FMNH2 to coenzyme Q- Coenzyme Q – lipid soluble electron carrier- Cytochrome c – accepts electrons from complex IV- Flavin mononucleotide – accepts electron from NADH in complex - Q cycle – funnels electrons from a 2-electron carrier to a 1-electron carrier- Catalase – converts reactive oxygen species into hydrogen peroxide- Proton-motive force – hydrolysis of ATP (A) 3 (B) 4 (C) 5 (D) 6 (E) 7