Question

scenario 6: the science fair enzyme experiment: a student is conducting a science fair project to investigate how different environmental factors affect the rate of an enzyme - catalyzed reaction. the student chooses to study amylase, a common enzyme found in human saliva that breaks down starch into simple sugars. the student sets up a series of experiments, measuring the rate at which amylase breaks down starch under varying conditions of temperature, ph, and substrate concentration. the students data is compiled in the following graph: using the graph that shows substrate concentration, describe how the reaction rate changes as the reaction rate increases and then levels off; the enzymes active sites have become saturated, and all of them are constantly working the reaction rate decreases; the enzymes active sites are being blocked by excess substrate the reaction rate stays the same; the enzyme is only affected by changes in temperature the reaction rate increases indefinitely; the enzymes active sites are continuously binding with new substrate

Explanation:

Enzymes have a limited number of active - sites. As substrate concentration increases, more active - sites bind to substrate and the reaction rate increases. Once all active - sites are saturated, adding more substrate does not increase the rate as all active - sites are already in use.

Answer:

The reaction rate increases and then levels off; the enzyme's active sites have become saturated, and all of them are constantly working.