作者star7799 (star7799)
看板medstudent
标题Re: [申覆] 医学(二) 27
时间Wed Aug 4 13:33:32 2010
※ 引述《timothy70417 (绝地武士)》之铭言:
27 下列调控酵素活性的方式,何者为不可逆的(irreversible)?
A 异位调节(allosteric regulation)
B 共价修饰(covalent modification)
C 酶原(zymogen)的蛋白水解切割(proteolytic clevage)
D 非竞争型抑制剂(uncompetitive inhibitor)的结合
答案C
线上的stryer也写到: fructose 1,6-bisphosphatase 是一个allosteric enzyme
他也会造成irreversible的例子
所以建议答案应该是 A或B或C
不知道这样可以吗?
16.3.4. The Conversion of Fructose 1,6-bisphosphate into Fructose 6-phosphate
and Orthophosphate Is an Irreversible Step
On formation, phosphoenolpyruvate is metabolized by the enzymes of glycolysis
but in the reverse direction. These reactions are near equilibrium under
intracellular conditions; so, when conditions favor gluconeogenesis, the
reverse reactions will take place until the next irreversible step is
reached. This step is the hydrolysis of fructose 1,6-bisphosphate to fructose
6-phosphate and Pi.
The enzyme responsible for this step is fructose 1,6-bisphosphatase. Like its
glycolytic counterpart, it is an allosteric enzyme that participates in the
regulation of gluconeogenesis. We will return to its regulatory properties
later in the chapter.
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1F:推 sa36599809:这题我也觉得很怪 08/04 12:25
2F:→ fangtu:我也写B的样子 08/04 12:48
3F:推 cestlavie523:我也写B~~ 08/04 12:53
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4F:推 lewdster0128:推~ 08/04 14:21