The number 3.45 represents the decomposition of
3.45 μmol of hydrogen peroxide in 3.0 mL of reaction
mixture to produce a decrease in absorbance at 240 nm
from 0.45 to 0.40 absorbance units. Further, t-min
corresponds to the time in minutes required for absorbance
at 240 nm to decrease from 0.45 to 0.40 absorbance
units, and 0.1 (in mL) represents the volume of the meat
extract. The catalase activity was expressed as units/g
sample.