Lab 7. Enzymes Exam Complete Study Guide With Solution Lab 7. Enzymes.pdf
Note: All your answers to questions must be in Red or other color (not
including blue) for easier grading. Points will be deducted if you do not
distinguish your answers.
Lab 7. Enzymes
Objectives:
Define the following terms: metabolism, reactant, product, substrate,
enzyme, denature
Describe the specific action of the enzyme catalase, include the
substrate and products of the reaction
List the factors that can affect the rate of a chemical reaction and
enzyme activity
Explain why enzymes have an optimal pH and temperature to ensure
greatest activity (greatest functioning) of the enzyme (be sure to
consider how virtually all enzymes are proteins and the impact that
temperature and pH may have on protein function)
Explain why the same type of chemical reaction performed at different
temperatures revealed different results/enzyme activity
Explain why warm temperatures (but not boiling) typically promote
enzyme activity but cold temperature typically decreases enzyme
activity
Explain why increasing enzyme concentration promotes enzyme
activity
Explain why the optimal pH of a particular enzyme promotes its
activity
Vocabulary:
Metabolism
Reactant
Product
Substrate
Enzyme
Catalyst
Denature
Activation Energy
Introduction:
Enzymes speed the rate of chemical reactions. A catalyst is a chemical
involved in, but not consumed in, a chemical reaction. Enzymes are proteins
that catalyze biochemical reactions by lowering the activation energy
Page 1 of 10 /2026 Lab 7. Enzymes.pdf
, Lab 7. Enzymes Exam Complete Study Guide With Solution Lab 7. Enzymes.pdf
necessary to break the chemical bonds in reactants and form new chemical
bonds in the products. Catalysts bring reactants closer together in the
appropriate orientation and weaken bonds, increasing the reaction rate.
Without enzymes, chemical reactions would occur too slowly to sustain life.
The functionality of an enzyme is determined by the shape of the enzyme.
The area in which bonds of the reactant(s) are broken is known as the
active site. The reactants of enzyme catalyzed reactions are called
substrates. The active site of an enzyme recognizes, confines, and orients
the substrate in a particular direction.
Enzymes are substrate specific, meaning that they catalyze only specific
reactions. For example, proteases (enzymes that break peptide bonds in
proteins) will not work on starch (which is broken down by the enzyme
amylase). Notice that both enzymes end in the suffix -ase. This suffix
indicates that a molecule is an enzyme.
Environmental factors may affect the ability of enzymes to function. You will
perform a set of experiments to examine the effects of temperature, pH, and
substrate concentration on the ability of enzymes to catalyze chemical
reactions. You will be examining the effects of these environmental factors
on the ability of catalase to convert H2O2 into H2O and O2.
Part 1: Testing Catalase Activity
Background Information:
Hydrogen peroxide is a toxic product of many chemical reactions that occur
in living things. Although it is produced in small amounts, living things must
detoxify this compound and break down hydrogen peroxide into water and
oxygen, two non-harmful molecules. The organelle responsible for destroying
hydrogen peroxide is the peroxisome using the enzyme catalase. Both plants
and animals have peroxisomes with catalase. The catalase sample for
today’s lab will be from a potato.
Question: When hydrogen peroxide is added, does a modest amount of catalase cause bubbles to
appear?
Hypothesis: Only hydrogen peroxide will cause the catalase enzyme to react.
Materials:
Two clean test tubes
Test tube rack
Ruler
1 mL graduated pipet
Catalase (from potato)
Page 2 of 10 /2026 Lab 7. Enzymes.pdf
Note: All your answers to questions must be in Red or other color (not
including blue) for easier grading. Points will be deducted if you do not
distinguish your answers.
Lab 7. Enzymes
Objectives:
Define the following terms: metabolism, reactant, product, substrate,
enzyme, denature
Describe the specific action of the enzyme catalase, include the
substrate and products of the reaction
List the factors that can affect the rate of a chemical reaction and
enzyme activity
Explain why enzymes have an optimal pH and temperature to ensure
greatest activity (greatest functioning) of the enzyme (be sure to
consider how virtually all enzymes are proteins and the impact that
temperature and pH may have on protein function)
Explain why the same type of chemical reaction performed at different
temperatures revealed different results/enzyme activity
Explain why warm temperatures (but not boiling) typically promote
enzyme activity but cold temperature typically decreases enzyme
activity
Explain why increasing enzyme concentration promotes enzyme
activity
Explain why the optimal pH of a particular enzyme promotes its
activity
Vocabulary:
Metabolism
Reactant
Product
Substrate
Enzyme
Catalyst
Denature
Activation Energy
Introduction:
Enzymes speed the rate of chemical reactions. A catalyst is a chemical
involved in, but not consumed in, a chemical reaction. Enzymes are proteins
that catalyze biochemical reactions by lowering the activation energy
Page 1 of 10 /2026 Lab 7. Enzymes.pdf
, Lab 7. Enzymes Exam Complete Study Guide With Solution Lab 7. Enzymes.pdf
necessary to break the chemical bonds in reactants and form new chemical
bonds in the products. Catalysts bring reactants closer together in the
appropriate orientation and weaken bonds, increasing the reaction rate.
Without enzymes, chemical reactions would occur too slowly to sustain life.
The functionality of an enzyme is determined by the shape of the enzyme.
The area in which bonds of the reactant(s) are broken is known as the
active site. The reactants of enzyme catalyzed reactions are called
substrates. The active site of an enzyme recognizes, confines, and orients
the substrate in a particular direction.
Enzymes are substrate specific, meaning that they catalyze only specific
reactions. For example, proteases (enzymes that break peptide bonds in
proteins) will not work on starch (which is broken down by the enzyme
amylase). Notice that both enzymes end in the suffix -ase. This suffix
indicates that a molecule is an enzyme.
Environmental factors may affect the ability of enzymes to function. You will
perform a set of experiments to examine the effects of temperature, pH, and
substrate concentration on the ability of enzymes to catalyze chemical
reactions. You will be examining the effects of these environmental factors
on the ability of catalase to convert H2O2 into H2O and O2.
Part 1: Testing Catalase Activity
Background Information:
Hydrogen peroxide is a toxic product of many chemical reactions that occur
in living things. Although it is produced in small amounts, living things must
detoxify this compound and break down hydrogen peroxide into water and
oxygen, two non-harmful molecules. The organelle responsible for destroying
hydrogen peroxide is the peroxisome using the enzyme catalase. Both plants
and animals have peroxisomes with catalase. The catalase sample for
today’s lab will be from a potato.
Question: When hydrogen peroxide is added, does a modest amount of catalase cause bubbles to
appear?
Hypothesis: Only hydrogen peroxide will cause the catalase enzyme to react.
Materials:
Two clean test tubes
Test tube rack
Ruler
1 mL graduated pipet
Catalase (from potato)
Page 2 of 10 /2026 Lab 7. Enzymes.pdf
