Boris Kozarski
Lab partner: Donovan Ortiz
9/23/16
Bio 118: A-65
GTA: Mian Li, UGTA: Shelby Schaffer
Intro: Enzymes are important biological molecules that help catalyze numerous reactions in the body. They are an arrangement of proteins designed to serve very specific roles. Enzymes contain active sites that substrates bind to. The enzymes then help orient those substrates so they achieve ideal reaction conditions. As a result, substrates are broken down much faster than they would on their own (Lawless 2016). Due to the fact that so many different arrangements of proteins are possible, it’s no surprise that so many reactions in the body are all able to proceed faster with the help of enzymes. In this lab, catalase was used to break down hydrogen peroxide and measure the reaction rates depending on the H2O2 concentration. The purpose of this was to see if the concentration of H2O2 affected the rate of the reaction. The hypothesis tested was that larger substrate concentrations should result in faster reaction rates because there would be more molecules to bind to the enzymes. Catalase was extracted from the liver because it is an enzyme that is responsible for breaking down toxic substances in the body. H2O2 is a toxic substance so this seemed appropriate. Factors that affect enzyme activity include temperature, pH, enzyme concentration, substrate concentration, salt concentration (Lawless 2016). Methods and Materials: .21 grams of the liver extract was collected in a mortar and left on the ice. …show more content…
10mL of distilled water was then poured in gradually using a graduated cylinder, and the mixture was ground up using a pestle in order to extract the enzyme from the liver (Lawless 2016). The enzymes mixed with the water and an aqueous solution was formed. It was important that the enzyme solution was kept on ice to keep it cold. Three test tubes were then filled with different concentrations of H2O2; the first contained 4mL of H2O2 and 0mL of water, the second contained 2mL of H2O2 and 2mL of water and the third contained 1mL of H2O2 and 3mL of water. 250uL of enzyme solution was then added to each test tube using a micropipette (Lawless 2016), and the height of the bubble columns was measured after 10 seconds (in centimeters). The test tubes were duplicated to obtain more accurate results. The effect of reaction rate based on substrate concentration was then measured. Results: Test tube 1 and 1’ contained 4mL of H2O2 and 0mL of water (4:4). Test tube 2 and 2’ contained 2mL of H2O2 and 2mL of water (2:4). Finally, test tubes 3 and 3’ contained 1mL of H2O2 and 3mL of water (1:4). 250uL of enzyme solution were added to each test tube and the averages of the 2 duplicated tubes for each trial were taken. The results were as follows: Avg. 1,1’: 1.5cm, Avg.2,2’: .55cm, Avg. 3,3’: .375cm. Discussion: The test tubes that contained higher concentrations of the substrate formed higher reaction columns than the test tubes that contained lower concentrations of substrate. “This is because, at higher concentrations of substrate, the enzymes will have a lot more molecules to bind to and will break those substrates down much faster.” (Worthington 1). “The rate of the reaction would also peak off at the very end because, at one point in time, all
Lab partner: Donovan Ortiz
9/23/16
Bio 118: A-65
GTA: Mian Li, UGTA: Shelby Schaffer
Intro: Enzymes are important biological molecules that help catalyze numerous reactions in the body. They are an arrangement of proteins designed to serve very specific roles. Enzymes contain active sites that substrates bind to. The enzymes then help orient those substrates so they achieve ideal reaction conditions. As a result, substrates are broken down much faster than they would on their own (Lawless 2016). Due to the fact that so many different arrangements of proteins are possible, it’s no surprise that so many reactions in the body are all able to proceed faster with the help of enzymes. In this lab, catalase was used to break down hydrogen peroxide and measure the reaction rates depending on the H2O2 concentration. The purpose of this was to see if the concentration of H2O2 affected the rate of the reaction. The hypothesis tested was that larger substrate concentrations should result in faster reaction rates because there would be more molecules to bind to the enzymes. Catalase was extracted from the liver because it is an enzyme that is responsible for breaking down toxic substances in the body. H2O2 is a toxic substance so this seemed appropriate. Factors that affect enzyme activity include temperature, pH, enzyme concentration, substrate concentration, salt concentration (Lawless 2016). Methods and Materials: .21 grams of the liver extract was collected in a mortar and left on the ice. …show more content…
10mL of distilled water was then poured in gradually using a graduated cylinder, and the mixture was ground up using a pestle in order to extract the enzyme from the liver (Lawless 2016). The enzymes mixed with the water and an aqueous solution was formed. It was important that the enzyme solution was kept on ice to keep it cold. Three test tubes were then filled with different concentrations of H2O2; the first contained 4mL of H2O2 and 0mL of water, the second contained 2mL of H2O2 and 2mL of water and the third contained 1mL of H2O2 and 3mL of water. 250uL of enzyme solution was then added to each test tube using a micropipette (Lawless 2016), and the height of the bubble columns was measured after 10 seconds (in centimeters). The test tubes were duplicated to obtain more accurate results. The effect of reaction rate based on substrate concentration was then measured. Results: Test tube 1 and 1’ contained 4mL of H2O2 and 0mL of water (4:4). Test tube 2 and 2’ contained 2mL of H2O2 and 2mL of water (2:4). Finally, test tubes 3 and 3’ contained 1mL of H2O2 and 3mL of water (1:4). 250uL of enzyme solution were added to each test tube and the averages of the 2 duplicated tubes for each trial were taken. The results were as follows: Avg. 1,1’: 1.5cm, Avg.2,2’: .55cm, Avg. 3,3’: .375cm. Discussion: The test tubes that contained higher concentrations of the substrate formed higher reaction columns than the test tubes that contained lower concentrations of substrate. “This is because, at higher concentrations of substrate, the enzymes will have a lot more molecules to bind to and will break those substrates down much faster.” (Worthington 1). “The rate of the reaction would also peak off at the very end because, at one point in time, all