When digestion has occurred, the broken down parts of carbohydrates, proteins and fats including vitamins and minerals are absorbed directly into liver. Liver acts as a filter against toxic substances entering into main blood system. Toxic substances can also be changed into substances that can be removed by kidneys. For example, ammonia is a toxic substance that comes from the breakdown of proteins; and liver changes ammonia into urea, which is easily handled by kidneys.
Proteins and other substances play major roles in the growth, reproduction and control of the cells in the body. Liver is important in the production of hormones. It also produces proteins needed for circulation, proteins for blood clotting, and antibodies needed by the immune system. Liver makes lymph as well as Kupffer cells, both of which help remove toxic substances from circulation.
Purpose
The purpose of this experiment is to determine the effect of temperature on liver enzymes. We tried to observe the reaction of liver enzymes on hydrogen peroxide (H2O2) at different temperatures. We tried our reaction at four different temperatures, –5°C, 25°C, 40°C, and 65°C. We wanted to find out at what temperature liver enzymes react the slowest, and what temperature reaction would be the fastest.
Hypothesis
**We expect liver enzymes to function at greater speed with a rise in temperature**
If the liver enzyme was put into H2O2 at –5°C, then the mixture would slowly sizzle until the liver enzyme fully disappears. → Slowest
If the liver enzyme was put into H2O2 at 25°C, then the mixture would bubble until the liver enzyme disappears. → Slow
If the liver enzyme was put into H2O2 at 40°C, then the mixture would bubble so much the liver enzyme would bubble right out of the test tube. → Fast
If the liver enzyme was put into H2O2 at 65°C, then the mixture would explode blowing the enzyme right out of the test tube. → Fastest
Materials
- –5°C liver
- 25°C liver
- 40°C liver
- 65°C liver
- Test tube
-
H2O2
- Stick
- Paper
Experiment
**Make four round paper disks (the small round remains from whole puncher)**
Put –5°C liver on the paper disk then push it down to the bottom of the H2O2 filled test tube. Calculate the time that it takes to rise up, also record the rise motion and H2O2 reaction.
Put 25°C liver on the paper disk then push it down to the bottom of the H2O2 filled test tube. Calculate the time that it takes to rise up, also record the rise motion and H2O2 reaction.
Put 40°C liver on the paper disk then push it down to the bottom of the H2O2 filled test tube. Calculate the time that it takes to rise up, also record the rise motion and H2O2 reaction.
Put 65°C liver on the paper disk then push it down to the bottom of the H2O2 filled test tube. Calculate the time that it takes to rise up, also record the rise motion and H2O2 reaction.
**The quicker the disk rises from the bottom, there is a faster reaction; and the more bubbles will form**
Data
Conclusion
My hypothesis that stated, if the liver enzyme was put into H2O2 at –5°C, then the mixture would slowly sizzle until the liver enzyme fully disappears, was true. The hydrogen peroxide sizzled a little, and the paper disk came up pretty slow, which meant a reaction was taking place at a slow rate. My hypothesis that stated, if the liver enzyme was put into H2O2 at 25°C, then the mixture would bubble until the liver enzyme disappears, was false. The reaction was slower than I anticipated. It was faster than the –5°C liver enzyme, but there was not an intensive amount of bubbling. My hypothesis that stated, If the liver enzyme was put into H2O2 at 40°C, then the mixture would bubble so much the liver enzyme would bubble right out of the test tube, was true. I was kind of shocked that the disk would come out so fast; and the reaction speed was quite amazing. Mt hypothesis that stated, if the liver enzyme was put into H2O2 at 65°C, then the mixture would explode blowing the disk right out of the test tube, was true. The reaction at this temperature was apparent even before the disk got a quarter of the way down the tube. It took us forever to get the disk to the bottom of the tube, because the hydrogen peroxide kept oozing out as the liver touched it.
Liver enzymes reactions slow down and last longer when they are in acidic medium. But on the other hand, enzymes reactions are faster in basic medium, but still last longer. The best reaction is at about a neutral pH on its own environment of liver, it is a quick time very rapid reaction. This experiment that I constructed showed the speeds of enzymes at various temperatures. The cold enzymes reacted slowly with the acidic hydrogen peroxide. And the hot enzymes reacted very quick and rapidly with the acidic hydrogen peroxide. What if we weren’t using acidic stuff like hydrogen peroxide, and instead we were using a basic medium. My hypothesis is that the cold enzyme would be crazy fast, and the hot would be unimaginable. I think this experiment shows what happens to food we eat, because your livers enzymes have to clean and help digest what we eat. So if we eat acidic food enzymes have to work harder, than when we eat basic food; and when we eat food of neutral pH the enzymes have a better medium for reactions.
