3.2 Enzymes
Enzymes speed up metabolic reactions by lowering energy barriers. Each enzyme has an optimal temperature and pH. Regulation of enzyme activity helps control metabolism.
To Think About:
What is the role of enzymes? How is enzyme structure related to enzyme function? What determines whether a substrate can interact with an enzyme? What happens to an enzyme after the completion of a reaction? How do enzymes facilitate chemical reactions in cells? What is activation energy in a chemical reaction? What are the different types of control groups? What is the use of each type of control group? How are control groups different from controlled variables? What does it mean for an enzyme to be denatured? How do changes in pH affect enzyme activity? How do changes in temperature affect enzyme activity? How do changes in enzyme concentrations affect the rate of reactions? How do changes in substrate and product concentrations affect the rate of reactions? How do competitive inhibitors affect enzyme activity? How do noncompetitive inhibitors affect enzyme activity?
Watch: AP Daily Video Enzyme Structure
Answer the Following Questions:
- What is the function of enzymes?
- Enzymes are usually made of _______________. (Bonus question: what is a ribozyme? Look it up :)
- The place where the reactant (also known as the _______________) interacts with the enzyme is called the _______________.
- The function of an enzyme depends on its _______________.
- Many enzymes end in the suffix -ase, for example, the breakdown of sucrose is catalyzed by the enzyme _______________.
- True or False Enzymes can be reused.
- Based on the study referenced at 2:30 in the video, write the statement best explains the chemical interaction between amylose and salivary amylase?
Watch: AP Daily Video Enzyme Catalysis-1
Answer the Following Questions:
- Why do enzymes usually facilitate only one type of reaction?
- What is activation energy?
- How do enzymes affect activation energy, and how does this affect the rate of reaction?
- A big part of your success on the AP exam will be determined by your ability to identify the components of an experiment. Pause the video at 2:45, and identify what would be the best control of this experiment.
Watch: AP Daily Video Enzyme Catalysis-2
Answer the Following Questions:
- Describe three differences between the control group and the experimental group.
- How is a negative control different from a positive control?
- What are controlled variables (aka constants) and why are they useful?
- In the peroxidase experiment in the video, what is the control group? Justify the use of it as a control group. Is it an example of a negative or positive control?
- In the polyphenol oxidase experiment in the video, what is a possible control group? Justify the use of it as a control group.
Watch: AP Daily Video Environmental Impacts on Enzyme Function
Answer the Following Questions:
- What is denaturation?
- List some environmental factors that can lead to enzyme denaturation.
- How does denaturation affect enzyme function?
- Why does an initial slight increase in temperature increase the rate of enzyme catalyzed reactions, but an larger more extreme and pronounced change in temperature decrease the rate of reaction?
- How is the effect of raising the temperature above the optimum for a given enzyme different from the effect of lowering the temperature below the optimum for a given enzyme?
- Why do changes in pH affect reaction rate?
- Explain how increasing substrate concentration affects the reaction rate.
- Explain how increasing enzyme concentration affects the reaction rate.
- Explain how the action of competitive inhibitors is different from noncompetitive (aka allosteric) inhibitors.
Supplementary Resources:
- Bozeman Science: Mr. Andersen’s Enzymes Video
College of DuPage: Enzymes Review
KScience: Enzymes
