Saliva, produced by glands in the mouth, plays an important role in the digestion of food. Saliva contains a chemical, called amylase, that breaks down starch in the food we eat. A scientist conducts an experiment to investigate at which temperatures amylase works the best. He hypothesizes that the reaction will occur fastest if the amylase reaction is conducted near the normal human body temperature of 37ºC (degrees Celsius). In order to test his hypothesis, the scientist measures the reaction rate, which is how fast the amylase breaks down the starch at six different temperatures. The reaction rate is rated on a scale of 0 to 10, with 0 meaning no reaction and 10 meaning the fastest reaction. The results are recorded in the data table.

AMYLASE REACTION RATE BY TEMPERATURE

Temperature (ºC)

Reaction Rate

0

2

20 4
40 10
60 8
80 2
100 0
Based on the data, should the scientist accept or reject his hypothesis?
A He should reject the hypothesis because amylase reacts at all temperatures.
B He should accept the hypothesis because amylase reacts only at body temperature.
C He should reject the hypothesis because amylase reacts faster above body temperature.
D He should accept the hypothesis because amylase reacts fastest near normal human body temperature and slower above and below normal human body temperature.