Nutrition by Connor and Adil

Effect of Environmental Stimuli on Cell Division (Mitosis)

Mitosis Argument

Cell Division (mitosis) Arguementation

Enzyme Lab

Enzyme Lab Write-Up

Procedure 2: Determining the Effect of pH on Enzymatic Activity.

Question: How does  change in pH affect rate of enzymatic reaction?

Claim: As the concentration goes up, the enzymatic activity also goes up until it reaches its maximum of pH7 and decreases once again because there are not enough substrate molecules to interact with the enzyme.

Procedure:

1. 12 test tubes were prepared. 6 (substrate) tubes contained 7 mL of distilled water, .3 mL of hydrogen, and .2 mL of Guaiacol. The other 6 (enzyme) tubes contained 6 mL of specific pH solutions, and 1.5 mL of peroxidase.
2. A substrate and an enzyme were combined and as the reaction occurred we timed it from the beginning to the end (2 minutes).
3. We recorded the observed color for each tube every 20 seconds
4. A palette/ color chart was used to quantify the color changes observed.

Evidence:

Observed Color change of each test tube containing different pHs for 2 minutes

Color Change : represented in blue

pH	20 seconds	40 seconds	60 seconds	100 seconds	120 seconds	140 seconds
3	1	1	1	2	2	2
5	1	2	3	4	5	6
7	2	3	4.5	5.5	6	8
8	2	3	4	5	5.5	6
10	1	1	1	1	1	1

The chart above shows the color changes of the same substrate interacting with five different enzymes of varying pHs. The test tube which interacted with pH7 had the fastest color change of all 5 of the tubes. As the pH levels got further away from 7 they rates decreased to a point in which barely any color change was observed.

Reasoning:

As the number of enzymes decrease, the rate of reaction will decrease as well due there being less and less enzymes available to perform the reaction. This explains why any number greater than pH7 had a slowerd rate and less color changes. As the substrate level increases, so does the reaction rate due to there being more substrate for the enzyme present to work with. This explains why the rate increased and more color changes were observed as the pH increased to 7. A pH of 7 was probably the perfect mix of substrate and enzyme in which a reaction occurred effectively.

Procedure 3:

Question: In a time period of two minutes, what enzyme amount would reach the higher number of shade?

Claim: The tube which contains the most amount of pH buffer would reach the higher shade number because it contains the most pH.

Procedure:

1. 6 test tubes were prepared. 3 (substrate) tubes contained 7 mL of distilled water, .3 mL of hydrogen, and .2 mL of Guaiacol. The other 3 (enzyme) tubes contained varying amounts of ph7 buffer.
1. First enzyme: 6 mL of pH7 buffer, 1.5 mL of turnip peroxidase
2. Second enzyme: 4.5 mL of pH7 buffer, 3 mL of turnip peroxidase
3. Third enzyme: 6.75 mL of pH7 buffer
2. A substrate and an enzyme were combined and as the reaction occurred we timed it from the beginning to the end (2 minutes).
3. We recorded the observed color for each tube every 20 seconds
4. A palette/ color chart was used to quantify the color changes observed.

Evidence

Reasoning:

My hypothesis was correct, the tube containing the most amount of pH would reach the highest shade number since it has the most turnip peroxidase. This allowed for more interaction between the enzyme and the substrate and it increased the rate of reaction. The enzyme containing the 3 mL of ph7 reached 9 in two minutes while the other two only got to 7.

Enzyme Lab Write Up- Sana Ali

Procedure 2: Effect of pH

Research Question: In this lab my partner and I were determining what effect pH had on enzymatic activity. We had many pH amounts to choose from and we were determined to find which pH amount could produce the fastest reaction.

Hypothesis: After observing the pHs available we came to a hypothesis that a median pH can result in the most enzymatic activity. pH values that are too high or too low can have a slow effect on enzymatic activity. With this hypothesis in mind we began working on our experiment.

Procedure: In this lab we had five pairs of tubes totaling of 10 tubes. With each pair we labelled one tube enzyme and another tube substrate. To the substrate tubes we added 7 ml of distilled water, 0.3 mL of 0.1 percent hydrogen peroxide, and 0.2 mL of guaiacol for a total volume of 7.5 mL. To the enzyme tubes we changed the amount of pH added. We added 6.0 ml of a specific pH and 1.5 mL of peroxidase for a total volume of 7.5 mL. We used pHs 3, 5, 7, 8, and 10. After making the enzyme and substrate solutions we covered the tubes with parafilm until we were ready to combine them. Once we were ready we took one enzyme solution and one substrate solution and combined them into one tube labeled reaction. We covered the tube with the parafilm once again, inverted it twice to mix, and placed it on the tube rack. We timed the reaction for three minutes and recorded observations and took pictures of the solution’s color every 30 seconds. After the trial was over we compared our pictures and observations to the color chart.

Data:

Above is a graph showing the Progression of color values of each pH we used over the three minute trial. The x axis represents time and the y axis represents the color chart. Each line represent a different pH we used. For example, the blue line shows the progression of color of the enzyme with pH 7.

Claim: Having an intermediate pH can produce the most enzymatic activity compared to a pH that is too high or too low which would produce slow enzymatic activity.

Evidence:

		Color Chart
Tube	pH	0(sec)	30(sec)	60(sec)	90(sec)	120(sec)	150(sec)	180(sec)
1	7	2	3	5	6	8	9	10
2	5	1	4	6	8	9	10	10
3	8	1	4	5	6	7	8	10
4	3	1	1	1	1	2	2	2
5	10	1	1	1	1	1	2	2

Above is shown our data chart. Each tube we used is shown alongside its pH value. Over the 30 second increments the value reached from the color chart is shown.

Reasoning: Tube 2 which had a pH of 5 had the fastest reaction. By 150 seconds it reached 10 on the color chart. Other tubes that had relatively intermediate pH’s like tube 1 with pH 7 and tube 3 with pH 8 also had fast enzymatic activity. By the end of the 3 minute trial all of these tubes had reached 10 on the color chart. Tube 4 had a low pH of 3 and by the end of the 3 minute trial it reached 2 on the color scale. Too low of a pH does not allow the process to function its best. Tube 5 with a high pH of 10 also had slow enzymatic activity and reached 2 by the end of the 3 minute trial. Too high of a pH can denature the enzyme therefore slowing the reaction.

Procedure 3: Independent Investigation

Research Question: My partner and I now had some experience with the enzyme and substrate reactions. We decided to investigate the substrate solutions a little more. We decided to research how does changing the substrate concentration affect enzymatic activity.

Hypothesis: We hypothesized that increasing the substrate concentration would increase the enzymatic activity during a reaction. With this in mind we began our experiment.

Procedure: We took 4 pairs of tubes. Within each pair we labelled one enzyme and one substrate. The enzyme solutions all had 6.0 mL of distilled water and 1.5 mL of peroxidase for a total volume of 7.5 mL. Each tube that was labelled substrate were all different from one another because each had different substrate concentrations. Tube 1 had 1 mL of hydrogen peroxide, 0.2 mL of guaiacol, and 6.3 mL of water. Tube 2 had 0.2 mL of hydrogen peroxide, 0.2 mL of guaiacol, and 7.1 mL of water. Tube 3 had 0.5 mL of hydrogen peroxide, 0.2 mL of guaiacol, and 6.8 mL of water. Lastly tube 4 had 5 mL of hydrogen peroxide, 0.2 guaiacol, and 2.3 mL of water. After creating our enzyme and substrate concentrations we covered them with parafilm until we were ready to begin our reaction. When we were ready we uncovered the parafilm from each pair, combined them into one test tube labelled reaction, inverted the tube to mix, and covered the tube once again. We set the tubes on the test rack and ran the experiment for 3 minutes and recorded observations and took pictures of the solution’s color every 30 seconds. After the trial was over we compared our pictures and observation to the color chart.

Data:

Above is a graph showing the progression of color values of each of our solutions over the three minute trial. The x axis represents time and the y axis represents the color chart. Each line represents the different substrate concentration we used. For example, the red line shows the progression of color of the substrate concentration of 0.2mL.

Claim: After our experiment we saw that increasing the substrate concentration does not always speed up the reaction. An increase in both the enzyme and substrate concentration would allow for the enzymatic reaction to occur most efficiently.

Evidence:

		Color Chart
Tube	H2O2	0	30	60	90	120	150	180
1	1	2	4	5	6	8	9	10
2	0.2	2	3	5.5	8	9	10	10
3	0.5	1.5	3	5	6	7	8.5	9
4	5	2	4	5	7	8	9	9

Above is shown our data chart. Each tube is shown with the substrate concentration beside it. Under each 30 second increment the color reached by the solution is shown.

Reasoning:

As shown by the evidence Tube 2 with 0.2 hydrogen peroxide, 0.2 guaiacol, and 7.1 mL of water had the fastest reaction and reached 10 by 150 seconds. This was the fastest reaction when the substrate concentration was increased. My partner and I then decided to conduct one more trial where we increased both the substrate and enzyme concentrations. For the substrate we used 0.2 mL of guaiacol, 1 ml of hydrogen peroxide, and 6.3 mL of water. For the enzyme we used 3 mL of peroxidase and 4.5 mL of water. For this speedy reaction the solution was at 3 at 0 seconds for the color chart and  reached 10 by 120 seconds. This second test confirmed that increasing the substrate concentration alone is not enough. An increase in substrate and enzyme concentration can produce fast enzymatic activity.