6.4: The Respiratory System
21/10/2013 § Leave a comment
I hope everyone will forgive me for not writing a general summary about the reading this time, it’s been a busy – wait, I’m not going to apologise to the Internet, hahahAHAHAHA.
What am I doing with my life.
DATA BASED QUESTIONS
Page 140, concentration gradients
1. Explain why the oxygen concentration in the alveoli is not as high as in fresh air that is inhaled. The oxygen concentration in the alveoli is not high because the oxygen is used immediately for cellular respiration, which is constant, therefore oxygen is constantly depleted, while in fresh air, it can remain.
a) Calculate the difference in oxygen concentration between air in the alveolus and blood arriving at the alveolus. = 65 mm Hg
b) Deduce the process caused by this concentration difference. It is…. DIFFUSION???
- i. Calculate the difference in carbon dioxide concentration between air inhaled and air exhaled. = 24 mm Hg
- ii. Explain this difference. More carbon dioxide is exhaled because of cellular respiration. In humans, cellular respiration is powered by oxygen, which provides ATP, to produce carbon dioxide. Hence, when humans exhale, they exhale more carbon dioxide than they inhale carbon dioxide.
d) Despite the high concentration of nitrogen in air in alveoli, little or none diffuses from the air to the blood. Suggest reasons for this. Nitrogen cannot diffuse through the epithelial layers of the alveoli – it’s too big.