BIOCHEMISTRY
ENZYMES AND METABOLISM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Low temperatures denature enzymes and slows reactions
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Low temperatures change the structure of substrates and slow reactions
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Low temperatures means molecules are moving slower and so reaction rate is low
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Enzymes work best at low temperatures
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Detailed explanation-1: -At low temperatures, the enzyme and the substrate molecules are moving, but they’re not moving very fast, indicated by the small arrows from each molecule. This is because at low temperatures, the molecules have low kinetic energy.
Detailed explanation-2: -Lower temperatures lead to slower chemical reactions. Enzymes will eventually become inactive at freezing temperatures but will restore most of their enzyme activity when temperatures increase again, while some enzymes lose their activity when frozen.
Detailed explanation-3: -At low temperatures enzyme activity is low because the enzyme and substrate molecules have less kinetic energy so there are fewer collisions between them. At the optimum temperature, the kinetic energy in the substrate and enzyme molecules is ideal for the maximum number of collisions.
Detailed explanation-4: -Lowering the temperature slows the motion of molecules and atoms, meaning this flexibility is reduced or lost. Each enzyme has its zone of comfort, or optimal temperature range, within which it works best. As the temperature decreases, so does enzyme activity.
Detailed explanation-5: -As the temperature increases so does the rate of enzyme activity. An optimum activity is reached at the enzyme’s optimum temperature. A continued increase in temperature results in a sharp decrease in activity as the enzyme’s active site changes shape.