28 缺少維生素B1時會導致下列何種酶的活性降低？

 Succinate dehydrogenase Glucose 6-phosphate dehydrogenase

α-Ketoglutarate dehydrogenase Transaldolase

ANSα-Ketoglutarate dehydrogenase

Thiamine diphosphate

The synthesis of thiamine diphosphate (ThDP), also known as thiamine pyrophosphate (TPP) or cocarboxylase, is catalyzed by an enzyme called thiamine diphosphokinase according to the reaction thiamine + ATP → ThDP + AMP (EC 2.7.6.2). ThDP is a coenzyme for several enzymes that catalyze the transfer of two-carbon units and in particular the dehydrogenation (decarboxylation and subsequent conjugation with coenzyme A) of 2-oxoacids (alpha-keto acids). Examples include:

• Present in most species
• pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase (also called α-ketoglutarate dehydrogenase)
• branched-chain α-keto acid dehydrogenase
• 2-hydroxyphytanoyl-CoA lyase
• transketolase

29 下列何者不是穩定蛋白質三級結構的非共價交互作用力？

氫鍵（hydrogen bond） 凡德瓦爾力（van der Waals interaction）

離子交互作用（ionic interaction） 雙硫鍵（disulfide bond）

AND d

非共價交互作用力 NON COVALENT BOND

DISULFIDE BOND IS COVALENT

30 全世界約有10%人口具有葉酸缺乏症，下列相關敘述何者錯誤？

 葉酸缺乏可能和癌症、心臟病或腦部功能異常有關

葉酸缺乏時，會導致胸苷酸（Thymidylate）累積過量

葉酸缺乏時，DNA中易累積過量的尿素嘌呤（Uracil）

葉酸缺乏時，尿素嘌呤會被DNA修補系統辨認，導致DNA損壞

ANS B

tetrahydrofolic acid

THFA is involved with the enzymatic reactions necessary to synthesis of purine, thymidine, and amino acid.

folate deficiency increases uracil misincorporation

31 下列關於glucose在人類的紅血球中代謝的敘述，何者錯誤？

glucose代謝最終產物之一為lactic acid pyruvate可轉化為acetyl-CoA進一步代謝

ATP產量較少 glucose也可以利用pentose phosphate途徑代謝

ANS pyruvate可轉化為acetyl-CoA進一步代謝

IT IS ANAEROBIC METABOLISM

NOTE: DOES NOT GO TO ACETYL COA

TO LACTATE FROM PYRUVATE

32 控制血管栓塞藥物warfarin的作用，最主要是透過改變下列何種蛋白修飾（protein modification）的活性？

甲基化（N-methylation） 磷酸化（O-phosphorylation）

乙醯化（N-acetylation） 羧基化（γ-carboxylation）

ANS D

Warfarin and related 4-hydroxycoumarin-containing molecules decrease blood coagulation by inhibiting vitamin K epoxide reductase, an enzyme that recycles oxidized vitamin K to its reduced form after it has participated in the carboxylation of several blood coagulation proteins, mainly prothrombin and factor VII.

WARFARIN

vitamin K

Karboxylation