The adult human liver normally weighs between 3 – 6 pounds; it is a soft, pinkish-brown boomerang shaped organ. It is the second largest organ and the largest gland in the human body. Its position in the body is right under the ribcage on the right side of the upper abdomen. The liver lies on the right of the stomach and makes a kind of cradle for the gallbladder. The liver has four important jobs, production of bile to help digestion, cleaning up toxic substances and dead cells (detoxification), storing essential proteins, carbohydrates, vitamins and minerals (metabolism), and production of essential proteins and substances required for body functions.
Food is made up of carbohydrates, proteins, fats, vitamins and minerals. When we eat, food enters the stomach where the important phase of digestion occurs. Then the food passes on to small intestine where the main work of digestion takes place with the help of liver. Liver makes bile and digestive enzymes, special proteins that help to break down food to give energy. Bile is made by liver but is stored in gall bladder. Many waste products are unseen by bile before leaving the body as body waste.
In metabolism liver cells store carbohydrate as glycogen, which either comes straight from diet or is made from other sources of food. Carbohydrates are the main source of energy in your diet, and are preferred by your body. Liver controls the breakdown products of fat digestion, including cholesterol, which it uses for making bile. Proteins are broken down in digestive system into amino acids. These amino acids can then be used to make other proteins that the body may need. The most important are the plasma proteins, which are constructed in liver. Proteins are mainly tissue building foods for growth and repair. Left over proteins can be converted to stored energy. Fat-soluble vitamins are stored in liver cells. These include vitamins A, D, E and K. Liver also stores minerals, like iron from broken-down red blood cells, and diet sources.
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.
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, -5C, 25C, 40C, and 65C. We wanted to find out at what temperature liver enzymes react the slowest, and what temperature reaction would be the fastest.
**We expect liver enzymes to function at greater speed with a rise in temperature**
If the liver enzyme was put into H2O2 at -5C, then the mixture would slowly sizzle until the liver enzyme fully disappears. –> Slowest
If the liver enzyme was put into H2O2 at 25C, then the mixture would bubble until the liver enzyme disappears. –> Slow
If the liver enzyme was put into H2O2 at 40C, 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 65C, then the mixture would explode blowing the enzyme right out of the test tube. –> Fastest
1. -5C liver
2. 25C liver
3. 40C liver
4. 65C liver
5. Test tube
**Make four round paper disks (the small round remains from whole puncher)**
Put -5C 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 25C 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 40C 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 65C 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**
When liver disk was pushed half way to the bottom of test tube, the H2O2 started to sizzle. The disk swayed left and right as it came up.
When liver disk touched the H2O2, it started to sizzle. As the disk was pushed down the sizzling increased and the disk went up flipping.
When liver disk touched the H2O2, H2O2 bubbled. As the disk was pushed into test tube, the bubbling increased and the disk shot up and came out of the test tube.
When liver touched the H2O2, the H2O2 practically came oozing out of the test tube. And when we finally got the disk to the bottom of the tube it shot out with the oozing H2O2.
My hypothesis that stated, if the liver enzyme was put into H2O2 at -5C, 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 25C, then the mixture would bubble until the liver enzyme disappears, was false. The reaction was slower than I anticipated. It was faster than the -5C liver enzyme, but there was not an intensive amount of bubbling. My hypothesis that stated, If the liver enzyme was put into H2O2 at 40C, 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 65C, 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.