Enzyme Lab Report

Introduction: In class we are learning about enzymes, so we conducted a lab to test the effects of temperature on enzyme productivity. My group chose to use three different temperatures to test and a control group, which will be room temperature. These three temperatures are 50 degrees Celsius, 40 degrees Celsius, and 3 degrees Celsius.

Hypothesis: If the temperature affects enzyme productivity, then the rate of reaction will increase with the increase of temperature. When the temperature is above 40 degrees C, the reaction will be slow down, or cease to exist.

Independent Variable: temperature (Celsius)

Dependent Variable: rate of reaction (time and height of bubbles)

Controlled Variables: protein source (hydrogen peroxidase), type/amount of water, concentration of bindweed mixture, amount of bindweed mixture and hydrogen peroxidase

Justification of hypothesis: I know from previous research that heat affects enzymes both positively and negatively. The more the temperature increases, the more the rate of reaction increases, as well. However, there is a certain temperature at which the heat causes the bond to break because the protein is denatured. The enzyme changes shape and the substrate no longer fits with the enzyme.

Materials (Your Team’s Experiment):

• digital scale
• two handfuls of freshly picked bindweed with leaves (5 to 10 grams)
• mortar and pestle
• distilled water
• three 100-liter beakers
• 1 mL syringe
• hydrogen peroxide
• paper towels
• 8 glass test tubes
• test tube rack
• ice
• thermometer
• plastic ruler
• tape
• stopwatch

Procedure:

We are going to test the effect of temperatures on enzymes. There will be three different temperature that we will test: 50 degrees Celsius (hot), 40 degrees Celsius (body temperature), and 3 degrees Celsius (cold). The control will be room temperature (3 degrees Celsius)

Steps:

1. Set up the three different baths; water at set temperatures (50 degrees Celsius, 40 degrees Celsius, and 3 degrees Celsius) Warm up one bath, put ice in another, and set the third close to regular body temperature
2. Collect about two handfuls of fresh bindweed leaves.
3. Grind the leaves with the mortar and pestle, into a smooth substance
4. To create an extract for an accurate experiment, grind up the bindweed until you have 10 grams of mashed up bindweed. Then add water to the bindweed substance (55 mL)
5. Filter the water and bindweed mixture through a paper towel into a small plastic beaker until you have about 60 mL of bindweed extract (should look like green water). This will be more than enough extract, so there will be extra if you mess up.
6. Add 2 mL of the extract to four of the test tubes.
7. Then add the same amount (2mL) of hydrogen peroxidase to the other four test tubes.
8. Complete the next steps one group at a time.
9. Hold both test tubes (one hydrogen peroxidase and one with the bindweed extract) in one of the baths for two minutes.  (BEFORE YOU TAKE OUT THE TEST TUBES HAVE THE STOPWATCH AND RULER READY) Doing the reactions one by one, quickly take the two test tubes out of the bath and immediately combine them.
10. Measure the height of the bubbles every five seconds for thirty seconds.
11. Repeat process for remaining test tubes.
12. For the control group, do not alter the temperature of the test tubes. Just add them together at room temperature and measure the height of the bubbles the same way as the other reactions.

Data and Results:

See tables and graphs below.

 Control (20 degrees Celsius)

TIME (seconds)	HEIGHT (cm)
0	0
5	0
10	0.1
15	0.2
20	0.5
25	0.7
30	0.7

Temperature #1- Hot (50 degrees Celsius)

TIME (seconds)	HEIGHT (cm)
0	0
5	0
10	0.1
15	0.1
20	0.2
25	0.2
30	0.3

Temperature #2- Warm (40 degrees Celsius)

TIME (seconds)	HEIGHT (cm)
0	0
5	0
10	0.1
15	0.3
20	0.4
25	0.4
30	0.4

Temperature #3- Cold (3 degrees Celsius)

TIME (seconds)	HEIGHT (cm)
0	0
5	0
10	0
15	0
20	0
25	0.1
30	0.1

Data Analysis: To make the graph I used all the data from the tests and graphed them on one plane. By looking at both the tables and the graph, it is clear that the control (the blue line) had the greatest reaction. The slowest was the green line, or the cold test tubes. The red line was the hot temperature, while the yellow line represents the warm temperature.

Conclusions:

By analyzing the data, the data did support our hypothesis. The warmer temperatures produced a greater reaction, but the hot temperature (50 degrees Celsius) did not do as well as the warm and the control. However, the coldest temperature had the lowest height of bubbles after the two substances were mixed, meaning that the lowest reaction was the cold temperature, not the hot temperature. This was because when the test tubes were in the cold ice bath for two minutes, it dramatically dropped the temperature of both substances. The tubes felt ice cold, and the cold temperature caused such a small reaction because the enzyme was operating at below its optimum temperature. The hot temperature (50 degrees Celsius) had such a low reaction because the heat of both substances may have allowed the substrate or enzyme to become denatured, which means the enzyme and substrate could no longer work together to speed up the reaction rate. In conclusion, enzymes have the fastest and greatest rate of reaction in mild temperatures (room temperature or close to regular body temperature [40 degrees Celsius])