Why did the enzyme activity differ at 0c and 100c?

Answer 1

I will assume that you are talking about enzymes found in the normal human body. Enzymes function best at an optimal temperature (in our case, around 37 degrees celsius) because of the inherent tradeoff between reaction rates and protein stability. Remembering your elementary kinetics, the rate of an endothermic reaction (i.e. one that needs energy to function) is directly proportional to the temperature. Since by all means enzymes are biological catalysts, they follow this rule of thumb. However, remembering your biochemistry, higher temperatures lead to protein denaturization, wherein the activity of the enzyme becomes zero due to changes in the protein folding. Thus, in the case of human enzymes, we can expect to see optimal activity at body temp, low activity at lower temperatures, and no activity at very high temperatures.

It is important to note though that different enzymes have different optimal temperatures. For example, the DNA polymerase enzyme of Thermophilus aquaticus, a type of bacteria living near volcanic vents has an optimal temperature of around 70-80 degrees celsius!

== == the enzymes react faster when the temp. is lower b/c the enzyme would get used to the reaction to keep going and the normal body temp. is closer than 100 degrees celcius>>>......

Answer 2

At 0°C, enzyme activity is reduced because the molecules have lower kinetic energy, leading to slower reaction rates and less efficient enzyme-substrate interactions. At 100°C, the high temperature denatures the enzyme, altering its shape and disrupting its active site, which prevents substrate binding and reduces enzyme activity.

Answer 3

because enzymes get denatured at this temperature.

Answer 4

It becomes denatured and inactive.