Question

cellular respiration virtual lab
(1) what gas are you exhaling into the bromothymol blue solution?
(2) why did the bromothymol blue solution change?
(3) what is the impact of heart - rate and breath rate on the color change?
(4) what is cellular respiration?

Explanation:

Step1: Identify gas in exhaled air

The gas exhaled into the bromothymol blue solution is carbon - dioxide ($CO_2$). During cellular respiration, cells use oxygen and produce carbon - dioxide as a waste product.

Step2: Explain solution color change

Bromothymol blue is a pH indicator. When carbon - dioxide dissolves in water (the solution), it forms carbonic acid ($H_2CO_3$) which lowers the pH of the solution. Bromothymol blue changes color from blue (basic) to yellow (acidic) in response to the decrease in pH.

Step3: Analyze impact of heart and breath rates

Higher heart and breath rates mean more cellular respiration is occurring. This leads to more carbon - dioxide being produced and exhaled. So, the color change of the bromothymol blue solution will be more rapid and more pronounced as more carbon - dioxide is added to the solution, further decreasing the pH.

Step4: Define cellular respiration

Cellular respiration is the process by which cells break down glucose in the presence of oxygen to produce energy (ATP), carbon - dioxide, and water. The chemical equation is $C_6H_{12}O_6+6O_2
ightarrow6CO_2 + 6H_2O+\text{Energy (ATP)}$.

Answer:

1. Carbon - dioxide ($CO_2$).
2. Carbon - dioxide dissolves to form carbonic acid, lowering pH and changing the color of bromothymol blue from blue to yellow.
3. Higher heart and breath rates mean more carbon - dioxide is exhaled, leading to a more rapid and pronounced color change due to greater decrease in pH.
4. The process by which cells break down glucose in the presence of oxygen to produce energy (ATP), carbon - dioxide, and water with the equation $C_6H_{12}O_6+6O_2

ightarrow6CO_2 + 6H_2O+\text{Energy (ATP)}$.