[生醫] [生化]-台大94-生化A-幾題問題請教

看板Grad-ProbAsk作者super90579 (阿賢)時間16年前 (2010/02/23 16:58)推噓5(5推 0噓 14→)

留言19則, 3人參與討論串1/1

1. Which of the following amino acids possess the neurotransmitter function in vivo? (A)alanine (B)glutamic acid (C) leucine (D) phenylalanine (E)proline 這題補習班給答案為B 想請問一下這題為什麼不能選D PHE不是可以合成多巴胺作為神經傳導物質嗎? 2.Enzymes such as triose phosphate isomerase are referred to as having evolved to a state of "catalytic perfection," indicating that the enzyme? Ans. (E) converts substrate to product at a rate comparable to the diffusion-controlled limit 想請問 diffusion-controlled limit 是甚麼? 這題還有另一個選項是說她的Kcat會相當高這樣不對嗎? 3. The transition state has an estimated life time of about? (A) micro-second (B) mili-second (C)nano-second (D) pico-second (E)femto-second 這題就真的不知道了..沒頭緒 l版課本也查不到!? 4. Which of the statement is not true for ion channels? (A) Ion chnnels conducts ions at the expense of ATP (B) There are ion channels for sodium potassium and chloride (c) Ion channels conduct ions with selectivity (D) Ion channels function with much higher turnover rate than enzymes (E) Ion channels are composed of integral membrane proteins. 這題補習班答案給D 但A選項中離子通道不是不會耗ATP嗎? 5. Which of the ligands does not have a membrane receptor: (A) epinephrine (B) thyroxine (C) growth hormone (D) insulin (E) glutamic acid 這題也是沒頭緒@_@ 不過是不是用脂溶性的不必藉膜上接受器來傳導訊息的概念嗎? 6. The proteins of the Major Histocompatibility Complex (MHC) bind and display: (A) B cell fragments (B) immunoglobin fragments (C) antigen fragments (D) macrophage fragments (E) T cell fragments 這題補習班答案給E 但MHC不是是會辨認受感染細胞所產生的抗原片段嗎答案應該是C吧!? 謝謝!!! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 60.245.71.85

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michealking

02/24 16:18, , 1^F

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michealking

02/24 16:29, , 3^F

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