======Potato Catalase Hydrogen Peroxide Decomposition======


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**Alternative titles:** Testing Temperature Effects on Catalase
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====Summary====                   
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====Procedure====  
  - Gather a potato, hydrogen peroxide solution, a knife, heat-safe cup or beaker, and a way to chill and boil samples.
  - Cut the potato into three equal pieces: one for room temperature, one to freeze for at least 30 minutes, and one to boil for at least 5 minutes; cool the boiled piece to room temperature before use.
  - Chop and gently mash about 1 tablespoon of the room-temperature potato in a small cup to increase surface area.
  - Add enough hydrogen peroxide to fully cover the potato and watch for bubble formation.
  - Repeat the mash-and-add-peroxide steps for the boiled sample and for the frozen sample (allow the frozen piece to be chopped quickly while still cold).
  - Compare bubble production across the three conditions and note which sample shows the fastest and slowest reactions.
  - Record qualitative observations (bubble height, speed, duration) and relate them to enzyme activity.



====Links==== 
Enzyme Potato Experiment - Professor Revell: 
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Potato Catalyzed H2O2 Decomposition - North Carolina School of Science and Mathematics: 
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📄 Catalase and Hydrogen Peroxide Experiment - Education.com: [[https://www.education.com/activity/article/activator/]]\\


====Variations====
  * Test additional temperatures (refrigerated vs warm water bath) to build a simple enzyme activity curve.
  * Compare different plant sources of catalase (apple, liver substitute like spinach leaves) with equal masses.
  * Vary hydrogen peroxide concentration using store dilutions to explore substrate concentration effects.
  * Compare different particle sizes of potato by finely dividing some.




====Safety Precautions====
  * Wear eye protection; hydrogen peroxide can irritate eyes and skin.
  * Use only low-concentration household hydrogen peroxide (about 3%); higher concentrations require additional precautions and should be avoided in classrooms.
  * Handle knives and hot items (boiling water, hot potato) carefully; use tongs or heat-resistant gloves.
  * Do not ingest any materials; treat all samples as not food and dispose of mixtures in the sink with plenty of water.
  * Clean all surfaces and wash hands after the activity.




====Questions to Consider====
  * What gas forms the bubbles you observe, and how is it produced? (Oxygen gas, produced when catalase catalyzes the breakdown of hydrogen peroxide into water and oxygen.)
  * Why did the boiled potato show little or no bubbling? (Heat denatured catalase, changing its shape so it no longer functions.)
  * Why did the frozen potato react more slowly than the room-temperature sample? (Lower temperature reduces molecular motion, slowing enzyme-substrate collisions and reaction rate.)
  * How would changing the amount of potato affect the reaction? (More catalase increases the number of active sites, generally increasing the rate and bubble volume up to other limiting factors.)
  * If two room-temperature trials gave different bubbling, what variables might explain the difference? (Differences in potato surface area, mass, peroxide volume or freshness, or sample temperature and mixing.)