Literature has been published stating that the optimal pH for lactase activity is 4.8 with lactose. At this pH, what would be the closest value to the charge on the catalytically active amino acids? (Assume the pKa of the COOH group is 4.5)

with this one i know the answer in craters one reason i looked it up and i learned about it there is my evidence

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.