Unit 2: Enzyme Lab
Name: ____________________________
Period: _______
Experiment 1: Is Catalase Reusable?
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Observations after adding hydrogen peroxide to test tube #1:
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Gas being released: _______ (Answer: oxygen)
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Liquid in the test tube: _______________________________________________________
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Observations after pouring out the liquid and adding hydrogen peroxide again:
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Is catalase reusable?
- Claim: Yes, catalase is reusable.
- Evidence: Even after the first reaction with hydrogen peroxide, when I added more hydrogen peroxide to the same sample of liver, it produced bubbles again.
- Reasoning: This indicates that the catalase enzyme remained intact and functional after its initial reaction because it continued to catalyze the breakdown of hydrogen peroxide into oxygen and water, demonstrating its ability to be used multiple times.
Experiment 2: How does temperature affect catalase activity?
Hypothesis: _________________________________________________________
Observations after adding hydrogen peroxide to cooked liver in test tube #2:
- How does temperature affect catalase activity?
- Claim: Temperature has a significant effect on catalase activity.
- Evidence: The cooked liver did not produce any bubbles or very few, indicating little to no reaction with hydrogen peroxide.
- Reasoning: This could be because cooking denatures the enzyme, causing it to lose its active site and therefore its ability to effectively catalyze the breakdown of hydrogen peroxide.
Experiment 3: How does pH (adding an acid or base) affect catalase activity?
Hypothesis: _________________________________________________________
Part 1: Adding vinegar (acid):
- Observations:
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Part 2: Adding base solution:
- Observations:
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- How does pH affect catalase activity? Did one pH react better than the other?
- Claim: pH significantly affects catalase activity, with neutral pH being optimal.
- Evidence: In the test tube with vinegar, there was minimal or no bubbling observed compared to the reaction with the base solution.
- Reasoning: The acidic conditions likely denatured the catalase, while the base may have provided a more favorable environment, leading to a better reaction with hydrogen peroxide.
Post Lab Questions:
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How do environmental factors, temperature, and pH affect enzyme function?
- Enzymes are sensitive to environmental factors such as temperature and pH. High temperatures can lead to enzyme denaturation, where enzymes lose their structural integrity, rendering them incapable of catalyzing reactions, as seen in the cooked liver experiment. Additionally, extreme pH levels, both acidic and basic, can also denature enzymes or change their active sites, affecting their ability to catalyze. Generally, enzymes have an optimal temperature and pH at which they function best; deviations from these conditions can decrease their activity significantly.
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What role do enzymes play in your daily life? Why are enzymes important?
- Enzymes play a crucial role in many biological processes, including digestion, metabolism, and energy production. For instance, the enzyme amylase in saliva breaks down starches into sugars, facilitating digestion right from the moment food enters our mouths. This is critical for nutrient absorption and energy utilization. Without enzymes, these biochemical reactions would not occur efficiently, affording us the energy and resources necessary for survival. Their importance is highlighted in processes such as digestion, where enzymes efficiently transform complex molecules into simpler forms that our bodies can use.