Why does an enzyme not work as well if its active site is changed?
Answer (2)
Understanding Enzyme Activity
Enzymes are biological catalysts that speed up biochemical reactions by lowering the activation energy required. They do so by binding to specific molecules known as substrates at the active site of the enzyme. This active site is uniquely shaped to hold the substrate in the precise orientation necessary for the reaction to occur. Because enzyme specificity is akin to a lock and key mechanism, any alteration to the active site affects the enzyme's ability to bind substrates and catalyze reactions efficiently.
Factors Influencing Enzyme Function:
Temperature and pH levels play a pivotal role in enzyme function . Deviating from optimal temperature or pH ranges can lead to changes in the enzyme's structure, particularly in the active site. Such changes can prevent the enzyme from binding to substrates, resulting in decreased or abolished enzyme activity, a process known as denaturation. Moreover, enzymes adhere to the induced fit model, whereby both the enzyme and substrate exhibit flexibility, allowing minor adjustments in active site shape to accommodate the binding of the substrate.
Enzyme's Environmental Adaptations:
Enzymes are optimized to function best under the environmental conditions prevalent where their host organisms live. Enzymes from microbes in hot springs are effective at high temperatures, while human enzymes generally work optimally at body temperature (37°C). This adaptation ensures that enzymes catalyze reactions efficiently under specific conditions. Substrate concentration also affects enzyme function, with enzyme activity increasing with substrate concentration until a saturation point is reached.
The change in an enzyme's active site alters its ability to bind substrates, which is crucial for its function. Environmental factors like temperature and pH can denature enzymes, leading to a loss of efficiency. Maintaining the specific shape of the active site is essential for optimal enzyme activity.
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