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Transcript of Enzyme Lab
If the temperature is raised, then the rate of enzymatic reaction will increase because the additional heat provides the kinetic energy to speed up reactions.
If the temperature is lowered, then the rate of enzymatic reaction will decrease because the lower temperature decreases the amount of kinetic energy, slowing down enzymes and substrates.
cuvettes (16 x 150 mm)
0.1% hydrogen peroxide
dedicated pipettes (they don’t cheat and work really hard)
The temperature fluctuated throughout the lab, Didn't remain constant.
The substrate and enzyme tubes were mixed too early
Spilling of some of the Heated substrate-enzyme Mixture during the measuring of absorbency.
Possible inaccuracies in the measurement of each substance in the mixture.
Hot: Vmax = 0.49 absorbance/min
Room: Vmax = 0.47 absorbance/min
Cold: Vmax = 0.42 absorbance/min
The added heat did not significantly increase the rate of enzymatic reaction. The Vmax was consistently in the 0.40 - 0.50 absorbance/min range. The colder temperature lowered the rate of enzymatic reactions as its Vmax was lower than the control group’s.
How do abiotic and biotic factors
influence the rate of enzyme reactions?
BY: Alex Tran, Ivy Lu, Lena Nguyen,
Michelle Sears, Timothy Nguyen, VInh Nguyen
3. Make the control group by combining a substrate tube (4.7mL of distilled water, 0.2mL of hydrogen peroxide, 2 drops of guaiacol) and an enzyme tube (4.0mL of distilled water, 1.0mL peroxidase) to one cuvette.
4. Cover with a piece of Parafilm and set a timer. Put the cuvette into the spectrophotometer and record absorbance readings every minute for 5 minutes. The cuvette should be taken out every minute and shaken to keep the content’s consistency.
Procedures Part II
5. Make new substrate and enzyme tubes, but before combining, place them in an ice bath to cool down. This is one of the experimental groups. Record the temperature and repeat steps 3 and 4, instead placing the cuvette back into the ice bath every minute to keep the temperature equal.
6. Make new substrate and enzyme tubes, but before combining, place them in a beaker of water over a hot place. This is the other experimental group. Record the temperature and repeat steps 3 and 4, instead placing the cuvette back into the beaker every minute.
7. Put all the data into a graph.
Procedures part III
Independent Variable: Time in minutes
Dependent Variable: Absorbency
Constants: Salinity, pH, Concentration of substrate and enzyme, amount of guaiacol
Carleton University, Muise AM, and Storey KB.
"Regulation of Hexokinase in a Freeze Avoiding Insect: Role in the Winter Production of Glycerol." National Center for Biotechnology Information. U.S. National Library of Medicine, May 2001. Web. 20 Sept. 2015.
"Introduction to Enzymes." Temperature Effects.
Worthington Biochemical Corporation, Web. 20 Sept. 2015.
Scaraffia, PY, and Gerez De Burgos, NM. "Effects of
Temperature and PH on Hexokinase from the Flight Muscles of Dipetalogaster Maximus (Hemiptera: Reduviidae)." National Center for Biotechnology Information. U.S. National Library of Medicine, Sept. 2000. Web. 20 Sept. 2015.
An example of an enzyme would be hexokinase. Hexokinase catalyzes phosphorylation of glucose in the first step of glycolysis. The effects of temperature on the catalytic properties were tested from the flight muscles of Dipetalogaster maximus. The temperatures that were tested were at 20 degrees C, 30 degrees C, and 37 degrees C. From the article, catalytic efficiency, km, and vmax were higher at 37 degrees C than compared to 30 degrees C and 20 degrees C. This would indicate that glucose utilization and ATP production would increase as temperature rises.
1. Turn on the spectrophotometer 10 to 15 minutes before starting the experiment so that it can warm up. Set the wavelength to 470 nm.
2. To set the baseline, make a blank cuvette (containing 9mL of distilled water, 2 drops of guaiacol, and 1 mL of peroxidase). Set the spectrophotometer at zero absorbance, then put in the blank and set it to read 100% transmittance using the left dial.
Procedure Part 1
Moreover, another set of data of hexokinase was gathered from larvae of the goldenrod gall moth. In comparison of hexokinase properties at 22 degrees C and 4 degrees C, there was higher affinity for both glucose and ATP in the lower temperature. Furthermore, product inhibition by glucose-6-phosphate and ADP was reduced at 4 degrees C.
baking a cake at 120 degrees