Monday, November 18, 2013

Cell Respiration Lab

Purpose
The purpose was to compare the co2 emissions of germinating to dormant seeds. Also it was to determine the effect that temperature has on the cellular respiration. 

Introduction 
In this lab we measured the co2 that the germinating corn seeds produced. They are producing co2 because they are undergoing cellular respiration. A dormant seed has all the materials and food it needs to become a plant. When the seed becomes moist, the enzymes inside it start facilitating cellular respiration to make all the energy that the plant will need until it can go through photosynthesis.

Methods
In this lab we took the already germinated seeds and measured the amount of CO2 with the monitor to see what had the highest rate if respiration in ten minutes. Our group did corn, and we put it in ice cold water, to see what effect tempurature had on the rate of respiration. we used glass beads as a control group to make surety monitor was working properly.




Data
In our experiment the room was 24 degrees Celsius, and the cold water was 20 degrees celcius. The germinated seeds respirated at .66274 (ppm/s), and the germinated seeds in cold water respirated more at .68034 (ppm/s). The non germinated seeds respirated a ton less at .25721 (ppm/s). 








Graphs and Charts


Discussion
For the glass beads and the the non germinating seeds, both remained constant, neither showing any increase in CO2 output, which was to be expected. The germinating seeds at 24 degrees Celsius had a rate of .66 ppm/s while the cooler seeds at 20 degrees Celsius hade a rate of .68 ppm/s. This might not be accurate because the seeds at 20 degrees were not recorded for the full 10 mins. After 320 seconds, our group ran out of time. The rate of CO2 the seed produced could have slowed and ended with a slower rate after 10 minutes. If doing this experiment again, we would run each trial to the full time length. We would also soak the seeds in the ice water longer, further reducing their temperature. For the most part, the data did represent what we thought would be the results of the experiment. The glass beads are not alive, therefor not producing CO2. The no germinating seeds are not growing or using energy, so the would have no need to go through the process of cell respiration. Both germinating seeds would be going through cell respiration because they are growing. The cold seeds may have been producing more CO2 because they are trying to stay alive in the cold environment, and go through more cellular respiration to produce more heat. If I the data is inaccurate and the respiration rate should have been decreasing, it could be because the cold slowed the metabolic process down, affecting the CO2 output.

Conclusion 
The answers to the questions that we were finding were that the germinating seeds gave off more co2  than the dormant seeds, which means that they were respirating more. Also, the seeds germinated more at lower temperatures. 

References 
www.vrml.k12.la.us/rpautz/documents/.../respirationofgerminatingseeds.pd...

Tuesday, November 12, 2013

Enzyme Catalysis Lab

Enzymes and Catlysis Lab Report

Purpose
In this lab we were presenting how enzymes work and how they speed up reactions. 

Introduction
Enzymes are proteins that act as catalysts in a biochemical reaction. That means that they make a reaction go faster. They do this by lowering the activation energy, or the amount of energy needed to kick start a reaction. This allows reactions to take place at lower temperatures with more frequency. When an enzyme catalyze a a reaction it uses up the substrate to make a product. An enzyme can also be denatured, or broken, when taken out of its optimal pH or temperature, so one could stop a reaction by adding acid, because that would lower the pH. 

Methods - In the experiment, we took 10 ml of hydrogen peroxide and added 1 ml of catalase. We then swirled the solution and added sulfuric acid, denaturing the enzymes, stopping the reaction. Ww repeated this multiple times, but swirling for 30, 60, 90,120, 180 and then 360 seconds. We took a 5 ml sample of each and titrated the solution with potassium permanganate to fine out how much hydrogen peroxide was used up in each reaction. 

Data 
In the baseline there was 3.5 mL of hydrogen peroxide the whole time, in the final reading it started at 18.3, and after we put the enzyme in after 360 seconds the amount of hydrogen peroxide went down to 7.5 ml. The amount of hydrogen power oxide kept going down after we put in more KMnO4 because the enzymes caused the reaction to speed up and the ml drop after a shorter period of time.
Graphs and Charts 



Discussion
The overall trend of our results was that the longer we let the reaction go, the more substrate was used up. The only section that didn't follow this trend was at 30 seconds, but this may simply be because the measurement wasn't taken correctly. The initial and final reading go down every time because we titrate every time so more kmno4 was used. The amount of kmno4 used in the reaction goes down because that plus the amount of substrate has to add up to 3.5 (the baseline). The way to revise this experiment would be to make sure the titration Was done and read correctly. That is the point where it could've gotten messed up. The results of the experiment do support what we thought was going to happen because the longer the reaction goes, the more substrate gets used, just as we thought. 

Conclusion
There was no set question for answer for this lab, it was just an depth look at what we were studying in class. This experiment showed us the effects of a catalyst and it affects the rate of a reaction. We also better understood the idea of enzyme denaturing. In this case, there was a stop in the reaction because it was taken out of its optimal pH by adding sulfuric acid. 
References
The lab