Photosynthesis Lab Report

Introduction The lung is a spongy organ made up of of irregularly shaped air spaces called Alveoli. The alveoli are lined by a single layer of flat cells and supported by a mesh of fine elastic fibers. The alveoli are surrounded by a rich network of pulmonary capillaries (Couch and Berger, 2004). Our lungs are a network of connected tubes that bring oxygen from the air into our blood, nourishing the trillions of cells that make up our bodies. The lungs also clean the blood of carbon dioxide waste created when cells use oxygen (Natural Geographic, 2012). In experiment one I hypothesize that the effect of respiration changes on carbon dioxide, concentration in exhaled air will be greatest the longer the respiration rate is increased. I predict that during normal breathing the time it takes to detect the carbon dioxide will be greatest.
After hyperventilation I predict that it will take less time to detect the carbon dioxide compared to the normal breathing. Lastly I predict that after exercise the carbon dioxide will be detected the quickest compared to the other two tests. In experiment two I hypothesize that when blowing air into the phenol red there will be an increase in the pH due to the carbon dioxide being added. I predict that there will be a color change and the pH will become more basic.
Materials and Methods In lab experiment one, we gathered three test tubes; we labeled the first one N for normal, the second H for hyperventilation, and the third one E for exercise. Next we filled each test tube a quarter full with a calcium hydroxide solution making sure all three test tubes looked equivalent to each other. Next I began to exhale through a straw into the N marked tube while my partner timed me. I blew into the tube until it became a cloudy white color. After recording the time I then moved onto the hyperventilation tube. First I hyperventilated for thirty seconds and then exhaled into the test tube until it too became cloudy while my partner timed me. Lastly I ran in place for two minutes and then exhaled into the test tube marked E until it too became cloudy. In the second experiment that we did we only needed one test tube. I filled the test tube a quarter full of alkaline phenol red. I checked the pH of the sample using indicator paper. Next I added CO2 (carbon dioxide) to the test tube by blowing through a straw into the phenol red. After I blew into the test tube the pH of the solution was checked again.
Results
In experiment one, all test tubes eventually became cloudy due to the carbon dioxide.
The normal breathing test tube took the longest then after hyperventilation, and then after exercise had the biggest CO2 concentration because of how quickly it was detected. See Table 1. In the second experiment, the original pH of the alkaline phenol red was 4.0. After adding CO2 by exhaling, the color changed from a deep red to a bright red. The pH of the solution also changed; it changed to a 6.0 so it became more neutral by adding CO2 which is more basic then the alkaline phenol red. See Table 2.
Discussion I support my hypothesis for experiment one because the longer respiration was increased, the greater the carbon dioxide concentration was. In each test tube carbon dioxide was detected, but the more physical I became making my respiration rate increase, the quicker the test tubes changed to a cloudy white color. Test tube E (exercise) was the quickest to change from a white to a cloudy white color because of the carbon dioxide concentration was greatest during this period. I ran for two minutes making my breathing rate increase and stay increased longer then hyperventilation, which was only thirty seconds, and normal breathing. There was no potential for error, everything was equal in the measurements and all the times were precise. Though when I was comparing with another group, all of their times were shorter than mine. Their regular breathing time was about three minutes, where mine was over four. Their time after hyperventilation was less than two minutes and mine was over two minutes. Their time for after exercising was less than a minute thirty and that was the only one that matched up with my results. We all had the same pattern of the normal test tube taking the longest and hyperventilation in the middle and after exercising being the fastest color change. But I could just have a better respirator system because I am a distance runner, so possibly my CO2 levels very compared to the other groups doing this experiment. I support my hypothesis for the second experiment because I knew that carbon dioxide was not acidic so I knew the pH level would rise.
My prediction that there would be a color change went hand in hand with my hypothesis because I knew if there was to be a change then normally a color change would also occur. There was no potential for error, everything was straight forward and the measurements were exact. I checked my results and found everyone else who did this experiment got the same results so my data is
credible.
If someone who smoked did this experiment or one similar, he or she would find that their carbon dioxide concentration levels would be different compared to someone who did not smoke. People who smoke destroy their lungs. Their respiratory system doesn’t work the way it is meant to. So their results would show higher levels of carbon dioxide concentration and making their time after doing things such as exercising very quick compared to another person that does not smoke. Lung function normally peaks in the late teens and or early twenties. After the early twenties, lung function declines about one percent a year over the rest of a person 's lifetime. Lung function decreases about two percent a year for people who smoke (Mama’s Health, 2012).
If I was to do this experiment again I would incorporate someone who smokes to see the difference of the patterns. I would also get both men and women like another experiment did. The study groups for each of these experiments comprised equal numbers of men and women. There were no significant differences between study groups by age, height, weight, body mass index, transcutaneous oxygen saturation, or heart rate (Cope, Watson, Foster, Sehnert, and Risby, 2003). If I were to do this experiment I would use people with different ages, heights, weights, body masses, and heart rate. All those things would produce different data and give us a better understanding of the respiratory system and the different carbon dioxide concentrations.

Literature Cited
Berger, L. R and Couch, L. 2004. Biology for Health-Related Sciences and Non-Majors. Boston. Pearson Custom Publishing.
Cope, Keary A., Watson, Michael T., Foster, W. Michael, Sehnert, Shelley S., and Risby, Terence H. 2003. Effects of ventilation on the collection of exhaled breath in humans. American Physiological Society.
Lungs. Mama’s Health. Retrieved April 17, 2012 from http://www.mamashealth.com/ organs/lungs.asp
Lungs. National Geographic. Retrieved April 17, 2012 http://science.nationalgeographic.com/ science/ health-and-human-body/human-body/lungs-article/

Table 1
The Effect of Respiration Changes on CO2 Concentration in Exhaled Air Respiratory Treatment | Normal Breathing | After Hyperventilation | After Exercise | Reaction Time | 4:20 | 2:36 | 1:12 |

Table 2

Solution | Original pH | Original Color | After CO2 pH | Color Change | Phenol Red | 4.0 | Deep red | 6.0 | Bright red |