本题目来源于试卷: Interaction & Interdependence C.1 Enzymes & Metabolism，类别为 IB生物学
[单选题]
Purified enzymes are easily den12xxs) tmdl xul4)ipi:g si92 atured. Which of the following is the best way 7y-, kqzfpq:w to keep enzy 7p-q:f,zq ykwmes active for a longer period of time?
A. By adding acid to the solution containing the enzyme
B. By adding alcohol to the solution containing the enzyme slowly under cold conditions
C. Keeping the enzyme in a buffer solution at an appropriate pH in a refrigerator
D. Heating the enzyme to $100^{\circ}C$ and then storing it in an appropriate container
参考答案: C
本题详细解析:
By keeping the enzyme in a buffer solution at an optimupl5-3gf eju:q m pH, the enzyme will be stabilized and remain active for a longer period of time. By adding acid to the enzyme (Choice A), the pH will be lowered and may denature the enzyme, which is irreversible. The pH change will alter the charge on the enzyme, which can affect its solubility. pH changes can also prevent the enzyme from binding to the substrate by changing the shape of the active site. Alcohol (Choice B) can disrupt the intramolecular bonding of proteins and may alter their tertiary structure. Alcohol c-jl5eu p:qg f3an also denature proteins. Heating the enzyme to higher temperatures (Choice D) will cause the hydrogen bonds in the enzyme to break which affects the enzyme’s structure so that it can no longer bind to its substrate.
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