Absorbance at Various pH Levels

Question

Time (sec) pH 4 pH 5 pH 6 pH 7 pH 8 pH 9
20 0.003 0.025 0.055 0.146 0.005 0.004
40 0.009 0.109 0.152 0.300 0.015 0.008
60 0.012 0.195 0.255 0.432 0.038 0.010
80 0.020 0.215 0.341 0.552 0.065 0.012
100 0.023 0.333 0.413 0.659 0.081 0.013
120 0.025 0.360 0.478 0.755 0.090 0.013

The accompanying table represents the results of an experiment where the effects of pH buffers on an enzyme found in saliva (amylase) were studied. A spectrophotometer set at 500nm was used to measure absorbance at the various pH levels every 20 sec for 2 min. The higher absorbance values would indicate greater enzyme activity. All experiments were conducted at the same temperature.

Which statement correctly identifies the result that the optimum pH for amylase function is 7?
A) The pH with the lowest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.
B) The pH with the highest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.
C) At pH 9, the enzyme is denatured and will lose its function, but not its structure.
D) At pH 4, the structure of the enzyme will be altered, and the enzyme would not be able to catalyze the reaction.

Answer 1

B