Problem: How does exercise affect disposal of waste (CO₂) from cellular respiration? SBI4U: Cellular Respiration Lab

Pre-lab questions: a) Independent variable: Amount of the carbon-di-oxide produced during exercise. b) Dependent variable: Time c) Control Group: People who did perform any exercise or people who sitting idle. d) Constants: 5 ml of Bromothymol Blue, 50ml of water, 1 minute period of exercise. e) Safety Precautions: Don’t inhale the BTB solution while blowing the air. Label the beaker to avoid the mix-up of the data Don’t use same straw for blowing air by the different patients. f) Hypothesis: If someone exercise, then our muscles require lot of oxygen and produces high level of carbon-di-oxide waste. g) Rationale: During exercise, the blood vessels in the muscle dilate, resulting in more blood influx to muscle cells with high levels of oxygen. Lactic acid production during exercise raises the pH, causing carbonic acid to be converted to carbon-di-oxide, producing excess CO2 in the blood. Data-Analysis: 3. Cellular respiration in the body produces carbon-di-oxide. Cellular respiration is the cascade of the biochemical reactions that converts nutrients into the ATP and then releases the waste products such as carbon-di-oxide and water. 4. Cellular respiration maintains the amount of oxygen consumed and the amount of carbon dioxide released by the lungs in a normal state. During exercise, our muscles begin to work harder, our metabolism speeds up, and our cells convert available excess glucose or reserved fat into ATP to provide energy to the muscles. This overproduction causes our cells to emit more CO2 and signals our bodies to consume a large amount of oxygen. Reference: Your lungs and exercise. (2016). Breathe (Sheffield, England), 12(1), 97–100. https://doi.org/10.1183/20734735.ELF121 5. There is a distinction between the two experimental groups. Short bursts of intense exercise cause the cell to produce ATP via the anaerobic pathway, whereas prolonged light exercise causes the cell to utilise energy via the aerobic pathway. Group 2 has a faster colour change during intense exercise, indicating that they are doing short-term intense exercise and have an anaerobic metabolism. Group 3 has a faster colour change during light exercise, and their metabolism is aerobic, releasing less CO2 than the anaerobic metabolism. Reference: Paula Quinene (2019), "How Does Exercise Affect the Rate of Cellular Respiration?" Conclusion: 1. Address your hypothesis: Is exercise increases the production of the carbon-di-oxide by cell? The time taken to change the colour of the BTB solution is proportional to the amount of carbon-di-oxide. Exercise increases the amount of carbon-di-oxide released and time taken by the solution to change colour from blue to yellow is reduced. Yes, the results of this experiment support this hypothesis. The time taken for colour change after exercise is lesser to time taken for colour change before exercise. 2. Bromothymol is the acid indicator, when carbon-di-oxide is dissolved in water, it produces carbonic acid and lowers the pH of the solution. When the pH falls below 6.5, the colour changes to yellow. The intensity of the yellow colour, as determined by spectrophotometric analysis, indicates the concentration of carbon-di-oxide. 3. Cellular Respiration provides energy in the form of ATP to our body. 4. If our cells don't get enough oxygen while running, they switch to anaerobic metabolism, where carbohydrates are converted into ATP without the need for oxygen. Lactic acid and carbon-di-oxide are the end products of the anaerobic pathway. 5. 1) There are no duplicates of the experiment. It will impact the reliability of the experiment. 2) People's medical issues are not taken into account. Certain respiratory issues may indicate lower/higher carbon-di-oxide levels in a normal state. 3) Different levels of air blow are used. Different people blow air into the straw at different forces and time intervals, resulting in a data recording error.