Answer
a. Enzyme A - around 37°C, Enzyme B - around 78°C
b. Enzyme A - found in humans. Enzyme B - thermophilic
c. Since Enzyme A has been established as a human enzyme, its rate of functioning is also dictated by the temperature of the human body. When exposed to temperatures above its optimal rate, the enzyme loses its shape and functions. The heat breaks down the secondary and tertiary bonds in the enzyme.
Work Step by Step
a. The answer is taken from the graph provided. The highest point on each curve indicates the optimal temperature. Enzyme A is denoted in red. Enzyme B is denoted in blue.
b. Enzyme A's optimal temperature, 37°C, matches up with the healthy body temperature of a human being. Thus, it is more likely to be from humans. Since Enzyme B performs best at 78°C, it is most likely the thermophilic (heat-loving) bacteria.
c. 40°C (104°F) is not a temperature that human bodies typically reach, and such a high temperature places them at risk of death. As such, human enzymes are not adapted to such high temperatures, as they are usually only exposed to temperatures around 37°C. This is why the bonds break down at a higher temperature.
