Ib Biology Enzymes Ia

Biology Enzymes IA Design Introduction: Enzymes are globular proteins, they are responsible for most of the chemical activities of a living organism. They act as catalysts, substances that affects the reaction of other substances without being destroyed or altered during the process. They are extremely efficient in the body system of living organisms, one enzyme may catalyse over a thousand chemical reactions every second. But there are certain conditions that need to be fulfilled in order for the enzymes to work.

Temperature of the environment must be correct for each enzyme because different enzymes will have different temperature ranges in which they can live. pH levels in the environment must also be correct because if the environment around the enzyme is too basic or acidic, the enzyme will quickly denature. Hydrogen peroxide (H2O2) is naturally formed in living organisms, however it is very harmful and is broken down immediately by several enzymes including catalase. This enzyme catalyses the breakdown of hydrogen peroxide to water and oxygen.

Persons with acatalasemia (a hereditary condition) have extremely low catalase activity and, although present worldwide, it is more commonly found in Koreans. Hydrogen Peroxide is usually used as a topical disinfectant in wounds and the bubbling that is seen in the experiment is due to the oxygen gas released from the tested substance. Because of this, any cell that uses oxygen or lives in the presence of oxygen must have a way to get rid of the peroxide. One of these ways is to make catalase. Research Question: “In what manner will the product of the enzymatic reaction be released from the different substances placed with the test tube? “Different food items will produce different amount of bubbles when tested with the hydrogen peroxide” Variables: Table of Variables Independent Variable| Dependent Variable| Controlled Variable | Uncontrolled Variables| Different types of vegetables and fruits used for catalase testing| Amount of bubbles produced in the reaction| * Amount of hydrogen peroxide used to test each of the substances * Quantity of each substance * pH of the hydrogen peroxide| Temperature of the room | Table of Controlled Variables Variables | Method of Control |

Amount of hydrogen peroxide used to test each of the substances| Measured carefully with a measuring cylinder | Quantity of each substance| Each vegetables and fruit (with the exception of the Chinese cabbage) is cut to a block shape of 5? 1? 1cm dimension| pH of the hydrogen peroxide| Percentage concentration of hydrogen peroxide listed on the bottle | Apparatus List: * Test tube rack * Cutting knife * Cutting board * Stirring rod * 5 test tubes * 300ml glass beaker * Pipette dropper * 250 ml hydrogen peroxide of 3% concentration * Stopwatch * 1 red apple * 1 carrot * 3 branches of Chinese cabbage * 1 potato 1 onion Method Set up the cutting board and place the cutting knife carefully, place the all 5 test tubes on the test tube rack. Place a designated substance on the cutting board (any of the listed fruit/vegetables above) for the purpose of this method write-up we will use the red apple. Use the cutting knife to cut the piece of apple into halves, after that use the knife to cut 5 pieces of the red apples into 5? 1? 1cm of volume. Do the same for the carrot, potato and onions. For the Chinese cabbage rip out bits of leaves from the plant and roll them up into a cylinder-like shape that’s approximately a volume of ? 1? 1cm. At this point there should be 5 pieces (each) of red apples, carrots, potatoes and onions of a volume of 5? 1? 1cm + 5 rolled up pieces of Chinese cabbage. Place all these materials on the cutting board. Place all 5 of the red apples into the test tubes (1 piece for each test tube). Pour 250 ml hydrogen peroxide of 3% concentration into the 300 ml glass beaker. At this point, all apparatus should have been properly set-up and the experimentations should be able to commence. Using the pipette dropper to suck in 10 ml of the 3% hydrogen peroxide, drop 10ml of hydrogen peroxide into a test tube.

Repeat this for all of the test tubes. Use the stopwatch to count 10 minutes and observe the amount of bubbles being released from the bubbles. After 10 minutes have passed, record amount of bubbles released in each test tube. Pour the hydrogen peroxide and dump the waste material unto the sink and throw away leaf discs, rinse all the test tubes. Record all observed data. This is the experiment Repeat the experiment but instead of using red apples again, use the different vegetables that has been previously prepared. Test tube rack Test tube rack 5? 1? 1cm potato with 3% hydrogen peroxide 5? 1? 1cm potato with 3% hydrogen peroxide

Test tube Test tube Labeled Diagram: Data Collection and Processing Raw Data Table: Table 1: Amount of bubbles released from each test tube Processed Data Table: Table 2: Mean and standard deviation of amount of bubbles released from each test tube Graph: *Error bars represent the uncertainty of the bubble count of the experiment. Processed Data: Sample calculation of mean amount of bubbles produced: Where: Ex = Sum of all values n = Number of Values Where: Ex = Sum of all values n = Number of Values Formula: Mean= ? xn Calculation (Potato): 24+19+28+17+315 = 1195 = 23. 80 Mean of potato = 23. 80

Sample calculation of the standard deviation of amount of bubbles produced: Where: E = Sum of X = Individual measurements in sample Xbar = mean n = number of values Where: E = Sum of X = Individual measurements in sample Xbar = mean n = number of values Formula: Calculation (Potato): 2419. 765-1 = 2419. 764 = 604. 94 = 24. 60 Standard Deviation of potato = 24. 60 Sample calculation of the T-test of amount of bubbles produced: Where: X1 = mean of 1st sample X2 = mean of 2nd sample S1 = standard deviation of 1st sample S2 = standard deviation of 2nd sample N1&N2 = number of values Where: X1 = mean of 1st sample

X2 = mean of 2nd sample S1 = standard deviation of 1st sample S2 = standard deviation of 2nd sample N1&N2 = number of values Formula: Calculation (potato & red apple): (23. 80+8)5. 895+15 = 31. 80/1. 38 = 31. 80/1. 17 = 27. 18 T-test of potato and red apple = 27. 18 Conclusive Study & Evaluation Discussion By this point, it is clear that the bubbling process of each food item is distinct to their own properties. This statistical fact gives a possibility that each food item contained different amount of amylase. We know this because of the different number of bubbles produced by each food item.

For example, the average bubble release of the carrot is 56. 60 (±1) which is quite a lot of bubbles produced in 10 minutes. The onion, on the other hand produced very little amount of bubble compared to the carrot and producing an average of 2. 60 (±1) bubbles from the 5 trials conducted. The potato showed a good amount of bubbles produced, with the average of 23. 80 (±1) bubble produced from the 5 trials conducted. Thus, the potato contains the most amylase in it after the carrot. A theory to why carrots and potatoes contain more amylase than the other food items, is that both of the plant species belongs to the Asterids clade.

Both plants grow their fruits under the soil so it is possible that the food items grown under the soil. This is an exception to the onion however as the onion produced an average of 2. 60 (±1) bubbles. Conclusion Based on the knowledgeable findings of this experiment and relating back to the hypothesis of: “Different food items will produce different amount of bubbles when tested with the hydrogen peroxide” It is discovered that this statement is true. Also, the carrot is discovered to contain the most amount of amylase as it produced more bubbles than the rest of the food items Evaluation

Evaluation table: Procedure to be evaluated| Weakness| Improvements suggested| Design | Uncategorised test substances | Incomparable results due to the lack of similarity between the experimental substances| Organise and carefully select proper test substances | QUALITITY OF DATA| Only 5 trials were conducted| The amount of data could be greater| More trials could be conducted| PRECISION AND ACCURACY| The rate of bubbles being produced is sometimes too fast | Difficulty in counting specific amount of bubbles produced | Ask for assistance to count the bubbles |