Tran Nguyen
Professor Pate
Bio 180 Lab
CRN 60105
03/06/2018
Lab #4: Enzymes
Introduction
Every living organism has to chemically react in many pathways in order to survive. As a
result, we can define “metabolism” as the total chemical reactions an organism must have
performed. Exergonic reactions are spontaneous and in which, the energy of the products is
lower than of the reactants. In contrast, endergonic reactions are non-spontaneous because the
energy of the products is higher than of the reactants, that means they need energy inputs. In any
way, more or less, there should be an activation energy (Ea), which is where the energy of a
chemical reaction peaks from the reactants, and the reactants become products. In biology, we
have biological catalysts called “enzymes” which accelerate a reaction without getting consumed
in process, by lowering the activation energy.
The main purpose of this experiment is to investigate the kinetics of a reaction when an
enzyme is used as a catalyst, and how some factors influence the kinetics. In exercise 1, we
create a baseline mixture for further use for exercise 2. In exercise 2, we create 3 mixtures with 3
different enzyme concentrations to compare them with the baseline in exercise 1, as to see how
enzyme concentration affects the rate of reaction. In exercise 3, we also compare the baseline
mixture in different temperatures, to see how temperature affects the rate of reaction. In exercise
4, we add different pH buffers in the mixtures in order to figure the effect of pH to the rate of
reaction.
1
, Tran Nguyen
Data and Results
Table 1. Absorbance Spectrum for Mixture in Different Enzyme Concentrations
Absorbance (470 nm)
Time (seconds) Baseline (1x) 2x 1/2x 4x
0 0 0 0 0
30 0.15 0.37 0.12 0.66
60 0.31 0.55 0.25 1.06
90 0.42 0.66 0.35 1.26
120 0.50 0.73 0.43 1.38
150 0.55 0.78 0.47 1.46
Figure 1. The Effect of Enzyme Concentration on Peroxidase Activity
1.4
1.2
1
Absorbance
0.8
0.6
0.4
0.2
0
0 20 40 60 80 100 120 140
Time (seconds)
Baseline (1x) 2x 1/2x 4x
2
Professor Pate
Bio 180 Lab
CRN 60105
03/06/2018
Lab #4: Enzymes
Introduction
Every living organism has to chemically react in many pathways in order to survive. As a
result, we can define “metabolism” as the total chemical reactions an organism must have
performed. Exergonic reactions are spontaneous and in which, the energy of the products is
lower than of the reactants. In contrast, endergonic reactions are non-spontaneous because the
energy of the products is higher than of the reactants, that means they need energy inputs. In any
way, more or less, there should be an activation energy (Ea), which is where the energy of a
chemical reaction peaks from the reactants, and the reactants become products. In biology, we
have biological catalysts called “enzymes” which accelerate a reaction without getting consumed
in process, by lowering the activation energy.
The main purpose of this experiment is to investigate the kinetics of a reaction when an
enzyme is used as a catalyst, and how some factors influence the kinetics. In exercise 1, we
create a baseline mixture for further use for exercise 2. In exercise 2, we create 3 mixtures with 3
different enzyme concentrations to compare them with the baseline in exercise 1, as to see how
enzyme concentration affects the rate of reaction. In exercise 3, we also compare the baseline
mixture in different temperatures, to see how temperature affects the rate of reaction. In exercise
4, we add different pH buffers in the mixtures in order to figure the effect of pH to the rate of
reaction.
1
, Tran Nguyen
Data and Results
Table 1. Absorbance Spectrum for Mixture in Different Enzyme Concentrations
Absorbance (470 nm)
Time (seconds) Baseline (1x) 2x 1/2x 4x
0 0 0 0 0
30 0.15 0.37 0.12 0.66
60 0.31 0.55 0.25 1.06
90 0.42 0.66 0.35 1.26
120 0.50 0.73 0.43 1.38
150 0.55 0.78 0.47 1.46
Figure 1. The Effect of Enzyme Concentration on Peroxidase Activity
1.4
1.2
1
Absorbance
0.8
0.6
0.4
0.2
0
0 20 40 60 80 100 120 140
Time (seconds)
Baseline (1x) 2x 1/2x 4x
2
