2. When enzymes are heated, there is a progressive loss of catalytic activity over time. • Explain the biochemical basis for this fact. • A solution of the enzyme hexokinase incubated at 45°C lost 50% of its activity in 12 minutes, but when incubated at that same temperature in the presence of a very large concentration of one of its substrates, it lost only 3% of its activity in the same period of time. Suggest a biochemically plausible reason why thermal denaturation of hexokinase was slowed in the presence of one of its substrates.
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Their three-dimensional structure is crucial for their function. When enzymes are heated, the increased thermal energy can disrupt the weak bonds (such as hydrogen bonds, ionic bonds, and hydrophobic interactions) that maintain the enzyme's tertiary structure. Show more…
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When enzyme solutions are heated, there is a progressive loss of catalytic activity over time. Thus, a hexokinase solution incubated at 45 ° C for 12 minutes loses 50% of its activity; but when hexokinase is incubated at 45 ° C, in the presence of high glucose concentrations for the same time, only 3% of its activity is lost. Explain the reason for the denaturing variation of hexokinase due to the effect of temperature in the absence and presence of the substrate.
Patricia C.
When enzyme solutions are heated, there is a progressive loss of catalytic activity over time due to denaturation of the enzyme. A solution of the enzyme hexokinase incubated at $45^{\circ} \mathrm{C}$ lost $50 \%$ of its activity in $12 \mathrm{min}$, but when incubated at $45^{\circ} \mathrm{C}$ in the presence of a very large concentration of one of its substrates, it lost only $3 \%$ of its activity in 12 min. Suggest why thermal denaturation of hexokinase was retarded in the presence of one of its substrates.
Grigoriy S.
Under what conditions are enzymes denatured? Is denaturation reversible? Provide an explanation as to why denatured enzymes cannot catalyze chemical reactions. Why doesn't the rate of reaction continue to increase proportionally as the concentration of enzyme increases?
Keerti J.
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