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 silbrn .+ n +s::sd.uzebu ,gubn ih6oo+zo; )8x/vx2v asily denatured. Which of the following is the best way to keep enzymes activ+6,uo b8gzi;/ov h nobu2)x xve 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 optimum pH, the enzyme will be * pv6mf5u xz;vstabilized 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 can 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 th5muv6 ;fpx*vz at it can no longer bind to its substrate.
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