This exercise is based on the Beta-galactosidase and Lac Operon Labs that you just completed.
In a reaction between beta-galactosidase and ONPG the rate at which ONP appears is linear during the first ten
minutes of the reaction and then levels off.
1. Which of the following describes what is happening during the first ten minutes?
ONP concentration is increasing
Keq has been reached
Forward and back reactions are balanced
ONPG is decreasing at a constant rate
two of the above
2. Which of the following is true when you discover a significant interaction between two variables?
the effect of each variable is additive
both variables may have significant independent effects
the effect of one variable may alter the effect of the other variable
all but one of the above
3. If the same amount Na2CO3 is added 1:1 to a pH 6 solution and a pH 7 solution the final
pH of the two solutions will be
lower for the sloution that started at pH 7
impossible to determine
Figure . The effect of time on molecules per cell. Bars represent error. F= 14.49,df= 4,23 p=0.00
7. What should be added to the figure caption to make it more complete so it can stand alone? (List at least
8. "The number of molecules increased with time." Rewrite this topic sentence to include the following
words: E. coli, IPTG, Beta galactosidase
9. What is missing from this sentence? "There were almost five times as many beta galactosidase molecules/cell
after a 60 minute incubation."
10. Construct a sentence in which you repeat only one of the following data points but still point out the major
trend in the data. Time 0 = 10 molecules/cell, Time 15 = 20 molecule/cell, Time 30 = 30 molecules/cell