A student is investigating how substrate concentration affects the rate of an enzyme catalyzed reaction. Which three variables should be kept constant in the setup of the student's investigation?
A temperature of the reaction
B. amount of enzyme
Camount of substrate
D. amount of product
E pH of the reaction

The three variables that should be kept constant in the setup of the student's investigation:

CONSTANT VARIABLE:

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A. temperature of the reaction

B. amount of enzyme

E.  pH of the reaction

Explanation:  

To test various theories, experiments are typically conducted under a number of different conditions. Several variables must be established when planning studies to ensure reproducibility, precision, and validity of findings.

For example, while controls are held constant, different independent variables are strictly altered and analyzed - this ensures validity and may show whether external factors affected the experiment.

In this experiment, the rate of the reaction is the dependent variable. Thus all factors that may influence the final result, such as the temperature, pH, and enzyme concentration should be kept constant.

These factors can increase the reaction rate by altering the configuration of the enzymes, providing more collision energy, and increasing the collisions between and ratio of reactants. Increasing the concentration is expected to increase the frequency of collisions between reactants and thus speed up the rate.  

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