Enzymes are catalysts which are chemical substances that reduce the amount of activation energy needed for the reaction to begin. All enzymes are all proteins or RNA molecules that speed up metabolic reactions and help to break down poisonous chemicals in the organism’s body. An enzyme will only react if the enzyme fits well with the substrate, which is why they are similar to a lock and key. The substrate will bind to the enzyme at the active site and when this happens a slight change in the shape of the enzyme will occur.
This change of shape binds the enzyme to shape of the substrate and then weakens the chemical bonds of the substrate. When this happens it produces the activation energy that is needed for a chemical reaction to take place. The enzyme will only bind correctly with the substrate if the environmental conditions are to their liking. They like to work at room temperature and at the neutral range of PH. After the reaction the enzymes are not destroyed or changed and can be reused. Activation energy is what is needed for many chemical reactions to take place and for most reactions the amount of activation energy is very high. Grafton 2012) and (Possibilities and Hops 2009) Hypothesis (sees): If extreme changes in temperature affect the enzyme, then lowering or raising the temperature by amounts far out of normal range will cause the enzyme to function incorrectly. If extreme changes to the pH level affect the enzyme, then lowering or raising the acidity or alkalinity by drastic amounts will cause the enzyme to not work correctly. Procedures: Get safety goggles and put them on. For the normal catalane activity first put some hydrogen peroxide into a clean test tube, and then use tweezers to put a small piece of chicken liver in the test tube.
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Then push the liver down into the hydrogen peroxide using a stirring rod, and watch the bubbles of oxygen being leased. This heated up the test tube which was another clue that this reaction was an exercising reaction. After observing this then get another clean test tube and hydrogen peroxide in it and add a small piece of liver and watch the reaction occur in this one too and give off a lot of oxygen bubbles as well. After this, pour the liquid into yet another clean test tube and think about what would happen if more liver was placed in this liquid.
Place the liver into the liquid mixture of hydrogen peroxide and liver and the new mixture didn’t fizz as much as with just the hydrogen peroxide and one thing of liver. The thought of what would happen when adding more liver to the mixture was correct because it was thought that the mixture would cause a smaller reaction and it did. If more hydrogen peroxide was then added to the liver from the previous steps then there would be a more gas releasing reaction than adding more liver. Test this and it was true that more hydrogen peroxide would cause a larger reaction.
This proves that enzymes, such as chicken liver are reusable, while the substrates, such as hydrogen peroxide, are not. Next get four clean test tubes and put equal amounts of hydrogen peroxide in ACH and put a small piece of liver in one, a small piece of potato in another, the third a small piece of apple, and to the last one a small piece of carrot. After putting these in their respective test tubes, record the reaction rate of each substance in Table 1 and say that potato and liver were the only ones that contained catalane. Next part of the experiment was testing the effect of temperature on catalane.
Put a piece of liver into the bottom of a clean test tube and then cover it with a small amount of distilled water and placed the test tube in a boiling water bath or five minutes, make sure to use the test tube holder when handling the hot test tube. Predict that that the boiling of the liver would not have a very big reaction, if one at all. Remove the test tube from the hot water bath and cool it, then pour out the water and added some hydrogen peroxide and see that there was no reaction, which meant the prediction was correct.
After observing this, put equal amounts of liver into three clean test tubes and poured hydrogen peroxide in three other clean test tubes and then place one of each into an ice bath, room temperature water bath, and hot water bath. Then predict that the hot water bath and the ice water bath will have the smallest reactions because enzymes do not like to bind to their substrates when there are drastic temperature changes. After three minutes pour each test tube of hydrogen peroxide into its respective tube of liver and observe what happened.
Record the reaction rates in Table 2, and then graph the estimated reaction rate as a function of temperature on Graph 1 . The prediction was right because the ice bath one barely reacted, the hot water one didn’t at all, and the room temperature had the biggest reaction. Conclude that the optimum temperature or catalane is room temperature. The reaction for the cold water bath and hot water bath happened as it did because enzymes will not bind to their substrates when there are drastic changes to the environment. The last part of the experiment was testing the effect of pH on catalane.
First add hydrogen peroxide to three clean test tubes. The first test tube had some hydrochloric acid added to it to get an acidic pH and the second test tube had a smaller amount of hydrochloric acid added to it than the first test tube along with some sodium hydroxide to obtain a neutral PH. Then the last test tube had ore sodium hydroxide than the second one and that gave it a basic PH. Then predict what would happen when the catalane reaction when placed in an acidic environment, a neutral environment, and a basic environment.
Thought the acidic one would have no reaction, the neutral one would have the most reaction, and the basic one would have a rather small reaction. Next add a small piece of liver to each test tube and record the reaction rates in Table 3, and then make a graph of the reaction rates on Graph 2. The optimum pH on catalane is neutral. The effect of low pH is no reaction, neutral pH is a fairly good reaction, and basic H is a small reaction for enzyme activity, which means that the predictions were correct.
Data and Observations: Table 1: Relative Reaction Rates of Catalane From Various Tissue Types Sample Rate of Enzyme Activity (0-5) Observations of Enzyme Activity Liver 4 Very many bubbles; quickly fizzes and for long time Potato 2 A few bubbles, so slightly fizzy Apple No activity, so no reaction Carrot Table 2: Relative Reaction Rates of Liver Catalane as a Function of Temperature Temperature co Little reaction, so few bubbles Room Temperature A lot of big bubbles building up 1 coo No reaction so there were no bubbles
Table 3: Relative Reaction Rates of Liver Catalane as a Function of pH pH of Sample Acid No bubbles Neutral Quite a few bubbles Base A few bubbles Results and Discussion: From the tables and graphs filled with the data I collected by doing the lab I can draw some conclusions about what affects different changes in pH and temperature have on the reactions of enzymes. I learned that enzymes function the best when they are kept in their normal range of temperature and PH.
Enzymes work the best at room temperature and at a neutral PH. Room temperature is the optimum temperature for enzymes, and I also learned that they like it better at CO than at ICC. The best pH for enzymes is neutral and the second best is basic and what they do not perform well at is acidic. So I concluded that enzymes do not like to function correctly unless they are at their optimum pH levels and temperatures, which is why they need to have a fairly stable environment to function in.
This tells me that the cells I worked with can only function correctly when they are in a stable environment, with a room temperature and a neutral PH. Analysis: By analyzing the data I collected I can make a generalization about the activity of all enzymes. The generalization can make is that enzymes work more efficiently when they are in their normal range of temperature and pH, and not when there are drastic changes to their environments. This picture is courtesy of http://WV. ‘. Mortimer. Co. K/enzymes/enzymes. HTML First the substrate will bind to the enzyme at the active site, and then the next step is that the enzyme will slightly change shape as the substrate binds to it. After this the enzyme conforms to the shape of the substrate and then the products are released which is the activation energy need to have a chemical action and to speed it up. When the heat produced by the reaction of the enzyme catalane and hydrogen peroxide occurs in living cells, it gives off the product of activation energy.
This is needed for any chemical reaction to begin and the enzyme makes this to speed up the rate of reaction time. The conditions that I tested that slowed down or stopped the enzyme catalane were the raising or lowering in temperature or being placed in an acidic or basic location. These conditions resulted in the stopping or slowing down of the catalane because it was a drastic change from the enzymes normal environment which caused the enzyme and substrate to not bind correctly.