#enzyme #enzyeandtemperature #temperature #biology #textbook
Pg:- 74,75
Ch:- 5
Effect of Temperature on Enzyme Activity:
Optimal Temperature: Each enzyme works best at a specific temperature, known as its optimal temperature. For most human enzymes, this is around 37°C (normal body temperature).
Below Optimal Temperature:
Lower temperatures reduce the kinetic energy of molecules, causing fewer collisions between enzymes and substrates.
As a result, the reaction rate decreases.
Above Optimal Temperature:
Higher temperatures can increase the kinetic energy initially, speeding up the reaction. However, if the temperature rises too much, it disrupts the enzyme's structure.
Denaturation at High Temperatures:
At temperatures beyond the optimal range, the enzyme's three-dimensional structure, especially the active site, can become denatured.
Denaturation is often irreversible and renders the enzyme non-functional.
Adaptations in Different Organisms:
Enzymes from thermophilic organisms (living in high temperatures) are stable at higher temperatures. For example, Taq polymerase, used in PCR, works well at 70–80°C.
Enzymes in psychrophilic organisms (living in cold environments) are adapted to function at low temperatures.
Enzyme Kinetics and Temperature:
Reaction rates generally double with every 10°C increase in temperature (Q₁₀ effect), up to the enzyme's optimal temperature.
Beyond the optimal temperature, the rate decreases sharply due to denaturation.
1. Explain why enzymes from thermophilic organisms are useful in industrial processes that require high temperatures. Provide an example of such an enzyme and its application.
2. In human fever conditions, body temperature can rise above the normal 37°C. How might this elevated temperature affect enzyme activity in the body, and what consequences might this have for metabolic processes?
3. Describe how the concept of enzyme denaturation is applied when food is cooked at high temperatures. Why does cooking change the texture and digestibility of proteins?
4. Explain why psychrophilic enzymes are beneficial for certain cold-environment processes, such as laundry detergents designed for cold water. How do these enzymes maintain their functionality at lower temperatures?
5. If a lab experiment requires maintaining an enzyme’s activity over an extended period, how would temperature control be essential for the success of the experiment? What strategies could be used to ensure the enzyme remains functional?