Discussion: In this experiment is to observe the reaction between each of the fresh liver , boiled liver , pulped liver , potato cube , manganese dioxide(untreated) , and boiled manganese dioxide(cooled after heating) with hydrogen peroxide solution.The reaction is tested by using glowing wooden splinter. The biological concept used in this experiment is enzyme-substrate reaction. Several factors will affect the enzymatic reaction such as temperature , PH value , substrate concentration , enzyme concentration and the effect of activators.(Worthington Biochemical Corporation, n.d). Catalase is a common enzyme that can be found in almost all living organisms that is exposed to the oxygen. Decomposition of hydrogen peroxide to water and oxygen can be catalyze by catalase.(Louis , 1818 ).The equation that involved in this experiment is H 2O2 → H2O2 + O 2 . While the equation for the manganese dioxide react with hydrogen peroxide is same with the equation above,H 2O2 → H 2O2 + O 2 but the Mn is not shown in the equation because Mn act as a catalyst in the reaction.
The organelle that involved in this experiment respectively cytoplasm(plant and animal) , cell membrane(plant and animal) , cell wall (plant cell) and peroxisome(plant and animal cell). Organelle Peroxisome become the major role in this experiment. This is because hydrogen peroxide is potentially toxic to the cell it has the capability to react with other different molecules . So, peroxisome have that role to convert hydrogen peroxide to water and oxygen,thereby neutralizing the toxicity because it contained enzymes such as catalase, it acts as a cellular defense. (Christian, d. D, 1967)
Based on the experiment that observed. The reaction for the pulped liver in tube 3 was more vigorous compare to the liver with size 0.8cm x 0.8cm x 0.5cm in tude 1 . This is due to the fact the pulped liver will increase the total surface area of the liver,more enzyme can act on it. This result in the rate of reaction is higher . When proceed to the boiled liver in tube 2 a glowing wooden splinter is penetrated through the parafilm, it had been observed that the glowing wooden splinter become dimmer and slowly extinguished . This can conclude that the liver is cooked under high temperature the structure and surface configurations are altered. So the enzyme losses its catalytic functions and it can said to be denatured and no reaction occurs . Therefore no oxygen gas is produced.
When comparing the reaction between fresh liver in t ube 1 and fresh potato in tube 4 , more gas bubbles is produced in fresh liver compare to fresh potato. Meaning that liver has more enzyme catalase than potato. Liver contains more enzyme catalase because detoxification occurs in liver that required a larger amount of catalase to lower the activation energy, therefore the rate of reaction can be speed up. While potato has less enzyme catalase, therefore more activation energy required result in the rate of reaction become slower. On the others hand, Comparing the reaction between the both heated liver and manganese dioxide. It can observed that the manganese dioxide is more reactive that boiled liver. The difference is caused by the sensitivity of catalyst towards heat. Liver contains catalase which is biological enzyme that sensitive to temperature it will denatured in high temperature.But manganese dioxide is inorganic catalyst ,it is not sensitive to heat and it will not denature and loss its catalytic functions in high temperature.It can be said the reaction of treated manganese dioxide is highly compare to boiled liver because when A glowing wooden splinter penetrated through the parafilm a ‘pop’ sound is heard,wooden splinter ignites with bright yellow flame and white fumes this indicated the presence of oxygen gas . While the glowing wooden splinter in boiled liver tube 2 it becoming dimmer and slowly extinguished.
During the experiment, some of the error might be done inadvertently such as parallax error when measuring solution,It can be improve by placing the eyes perpendicularly to the scalar. Moreover, when covering the mouth of the tube using parafilm , there is a break in skin or a scar,the area must be covered with a sufficient of parafilm to prevent the gas escape for the tube and it will
cause the reaction become not accurate. When during the part of heating the tube and also burning the wooden splinter it should done by a same person carefully to prevent accident. Last but not least, wearing gloves at all time during the experiment to prevent chemical substance from damaging skin.
