Potato Catalase and Temperature

Medium

Does heat speed up or slow down the enzyme catalase? Catalase is a protein found in potatoes that breaks hydrogen peroxide into oxygen and water. The oxygen it releases can push a small piece of filter paper to the surface of a test tube. You soak filter paper in blended potato, then drop it into hydrogen peroxide held at eight temperatures from 15 to 50 degrees Celsius. You time how long the paper takes to float. Below 40 degrees the paper rises in seconds. Above 45 degrees it slows sharply, showing the point where heat begins to destroy the enzyme.

Hypothesis

The hypothesis is that at temperatures above 40°C, the enzyme will become less effective.

Science Concepts Learned

Enzymes

Heat can stop enzymes from working — and catalase in potatoes shows this clearly. Catalase breaks hydrogen peroxide into oxygen and water, and the oxygen it releases can push a small piece of filter paper to the surface of a test tube. Below 40 degrees Celsius, the paper rises in seconds. Above 45 degrees, the enzyme starts to break down and the reaction slows sharply, marking the temperature where heat begins to destroy it.

Hydrogen Peroxide Decomposition

When hydrogen peroxide breaks apart into water and oxygen gas, the oxygen released can do physical work. Catalase in potatoes drives this decomposition. The released oxygen pushes a small piece of filter paper to the surface of a test tube, giving you a visible way to measure how fast the reaction occurs.

Reaction Rate

Reaction rate — how fast a chemical change happens — is strongly controlled by temperature. The enzyme catalase breaks hydrogen peroxide into oxygen and water. Below 40 degrees Celsius, the filter paper rises in seconds, meaning the reaction is fast. Above 45 degrees it slows sharply, showing the point where heat begins to destroy the enzyme and the chemical change nearly stops.

Catalase

Catalase is a protein in potato tissue that breaks hydrogen peroxide into water and oxygen. The released oxygen pushes a small piece of filter paper to the surface of a test tube. Below 40 degrees the paper rises in seconds, but above 45 degrees it slows sharply.

Enzyme Denaturation

Enzyme denaturation has a threshold temperature where the damage becomes obvious. Catalase in potatoes breaks hydrogen peroxide into oxygen and water, and the released oxygen pushes filter paper to the surface of a test tube. Below 40 degrees the paper rises in seconds, but above 45 degrees it slows sharply — heat changes the enzyme's shape, and once that shape changes, the enzyme stops working.

Temperature and Enzyme Activity

Enzymes speed up as temperature rises, but only to a point. Above that threshold, heat changes the enzyme's shape and it stops working. Catalase in potatoes breaks hydrogen peroxide into oxygen and water quickly below 40 degrees, but above 45 degrees the reaction slows sharply as the enzyme begins to break down.

Method & Materials

You will cut a potato into small pieces, blend it with water, and dip filter paper into the mixture. You will also fill 8 beakers and 8 test tubes with hydrogen peroxide and water, and adjust the temperature of the water in each beaker. Finally, you will place the filter paper into the test tubes and measure the time it takes for the paper to float to the top.

You will need a potato, a blender, filter paper, 8 beakers, 8 test tubes, a hot plate, a packet of ice, a bottle of hydrogen peroxide, a stopwatch, a thermometer, scissors, tweezers, a glass rod, and a marker pen.

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Results

The experiment showed that the filter paper floated very soon at temperatures below 40°C. At temperatures above 45°C, the paper took a longer time before floating. This proves that the hypothesis is true, and that at temperatures above 40°C, the enzyme Catalase will become less effective.

Why do this project?

This science project is interesting because it explores how temperature affects the enzyme Catalase, which is found in almost all living organisms and helps to convert hydrogen peroxide into oxygen and water.