Bio 155 Lab Report
Effect of Enzyme
and Substrate Concentration on Reaction Rate
by Zachary A. Poché
Biology 155 Laboratory
October 15, 2014
Lab Partners:
Cade White, Hannah Ragas, Russheka Aremillion
ABSTRACT
In order to increase the reaction rate, substrates attach to the active site of enzymes which
decrease the activation energy required to convert substrates to products. We examined the effect of
enzyme concentration and substrate concentration on the overall rate of the reaction. To determine the
effect of enzyme concentration and substrate concentration on the reaction rate, we performed a serial
dilution of enzymes to get test tubes with full, one-half, one-fourth, and one-eighth concentrations. We
then used a spectrophotometer to get the absorbance reading over time, and we used these readings to
determine the reaction rate. We did the same thing with a serial dilution for substrate concentration, and
we found the reaction rate for these as well. We found that as enzyme concentration decreased, the
reaction rate decreased as well. For example, the rate of the reaction at one-half enzyme concentration
was 0.95 while the rate of the reaction at one-eighth enzyme concentration was 0.32. We also found
that as substrate concentration decreased, the reaction rate also decreased. For example, the reaction
rate at one-half substrate concentration was 0.089, and the reaction rate at one-eighth substrate
concentration was 0.011. Overall, our results show that enzyme and substrate concentrations both have
an impact on the rate of the reaction.
INTRODUCTION
All cells depend on chemical reactions in order to survive (Schultz 2006). The amount of energy
required to convert substrates to products in these chemical reactions is called the activation energy.
Proteins called enzymes help to decrease the reaction rate of these chemical reactions by lowering the
activation energy required. Reactions that require less
and Substrate Concentration on Reaction Rate
by Zachary A. Poché
Biology 155 Laboratory
October 15, 2014
Lab Partners:
Cade White, Hannah Ragas, Russheka Aremillion
ABSTRACT
In order to increase the reaction rate, substrates attach to the active site of enzymes which
decrease the activation energy required to convert substrates to products. We examined the effect of
enzyme concentration and substrate concentration on the overall rate of the reaction. To determine the
effect of enzyme concentration and substrate concentration on the reaction rate, we performed a serial
dilution of enzymes to get test tubes with full, one-half, one-fourth, and one-eighth concentrations. We
then used a spectrophotometer to get the absorbance reading over time, and we used these readings to
determine the reaction rate. We did the same thing with a serial dilution for substrate concentration, and
we found the reaction rate for these as well. We found that as enzyme concentration decreased, the
reaction rate decreased as well. For example, the rate of the reaction at one-half enzyme concentration
was 0.95 while the rate of the reaction at one-eighth enzyme concentration was 0.32. We also found
that as substrate concentration decreased, the reaction rate also decreased. For example, the reaction
rate at one-half substrate concentration was 0.089, and the reaction rate at one-eighth substrate
concentration was 0.011. Overall, our results show that enzyme and substrate concentrations both have
an impact on the rate of the reaction.
INTRODUCTION
All cells depend on chemical reactions in order to survive (Schultz 2006). The amount of energy
required to convert substrates to products in these chemical reactions is called the activation energy.
Proteins called enzymes help to decrease the reaction rate of these chemical reactions by lowering the
activation energy required. Reactions that require less