49. Which of the following polarity pattern is   correct  ?
(A)
(B)
(C)
(D)
(E)

45. Which of the following statements about the reactions involved in the synthesis of deoxyribonucleotides is   false  ? (A) Deoxyribonucleotides are derived from the corresponding ribonucleotides by direct reduction at the 2'-carbon atom of the D-ribose to form the 2'-deoxy derivative. (B) Formation of deoxyribonucleotides is catalyzed by ribonucleotide reductase, in which its substrates are ribonucleoside diphosphates. (C) Glutathione serves as a reducing agent for glutaredoxin in deoxyribonucleotide synthesis. (D) Ribonucleotide reductase is notable in that its reaction involves free radicals in biochemical transformations. (E) The immediate precursor of thymidylate (dTMP) is dUMP. The conversion of dUMP to dTMP is a reaction of deamination.

46. Which amino acids are transaminated by the branched-chain amino acid aminotransferase? (A) valine, isoleucine, and leucine. (B) proline, valine, and alanine. (C) leucine, isoleucine, and phenylalanine. (D) leucine, isoleucine, and proline. (E) lysine, valine, and leucine.

47. Threonine is converted into acetyl-CoA and pyruvate while proline is converted into α-ketoglutarate. Classify each of these amino acids. (A) Threonine is ketogenic； proline is ketogenic. (B) Threonine is ketogenic and glucogenic； proline is ketogenic. (C) Threonine is ketogenic； proline is glucogenic. (D) Threonine is ketogenic and glucogenic； proline is glucogenic. (E) None of the above.

48. Which of the following statements explains why allopurinol is able to prevent gout? (A) It binds to uric acid thus preventing the formation of uric acid crystals. (B) It acts as a diuretic to increase the elimination of uric acid. (C) It inhibits the production of uric acid and allows for the more highly soluble xanthine and hypoxanthine to be excreted from the body. (D) It stimulates the purine salvage pathway, thus eliminating the need for production of uric acid. (E) None of the above.

50. Given this saturated fatty acid (shown below), how many ATPs can be produced when the fatty acid is metabolized completely? Some useful information:  i. In the TCA cycle, one acetyl-CoA gives 3 moles of NADH, 1 mole of FADH2, and 1 mole of GTP.  ii. One mole of NADH produces 2.5 mole of ATP. iii. One mole of FADH2 produces 1.5 mole of ATP. (A) 30. (B) 34. (C) 36. (D) 50. (E) 52.

1.若有二力平行且力大小相等、方向相反、不在同一直線，則稱為：(A)扭矩(B)力偶矩(C)彎矩(D)力矩

2.如圖所示，有一空間平行力系，試求此力系之合力型式為：(A)一單力(B)一力偶(C)一單力+一力偶(D)0(平衡狀態)

3.如圖所示之桁架，a桿件之桿件內力為(A)+25kg(B)-37.5kg(C)+42.5kg(D)-50kg

4.如圖所示，梯子(重量忽略不計)斜靠光滑牆上，今重量W之甲生由地面沿梯子上爬，若在上爬過程中，梯子並未滑動，而牆壁和梯子之作用力為F1，地面作用於梯子的正向力為F2，摩擦力為F3，則上爬過程中，F1、F2及F3之變化為？(A)F1由小變大，F2不變，F3由小變大(B)F1由大變小，F2不變，F3由大變小(C)F1由小變大，F2不變，F3由大變小(D)F1由大變小，F2由小變大，F3由大變小

5.如圖所示，試求30kg之力，對A點之力矩大小為(A)0kg-m(B)10kg-m(C)20kg-m(D)28.28kg-m