As temperature increases across a biologically active range

As temperature increases across a biologically active range where the protein is still active, how do you expect enzyme reaction rates to change and why? As temperature decreases?

Solution

Generally, increase in temperature leads to increase in rate of reaction up to optimum temperature levels. Due to increase in the temperature levels, the molecules which have been in motion, increases /speeds up their motion. This leads to higher formation of enzyme-substrate complexes, as higher temperatures also lead to increase the speed of enzyme. But if the temperature increases above the optimum level, rate of enzymatic reaction gets lowered. The reason is due to altered shape of the enzyme. The hydrogen bonds within enzymes break which leads to denaturation of enzymes at temperatures higher than optimum level. Due to this the number of substrate-enzyme complexes formed becomes low due to high denaturation of enzymes.