2.Diffusion is the key mechanism of gaseous exchange,still presence of haemoglobin pigment is a crucial factor in our blood based on which our oxygen requirement is satisfied. Explain the statement.
Answers
Answer:
Respiratory system, the system in living organisms that takes up oxygen and discharges carbon dioxide in order to satisfy energy requirements. In the living organism, energy is liberated, along with carbon dioxide, through the oxidation of molecules containing carbon. The term respiration denotes the exchange of the respiratory gases (oxygen and carbon dioxide) between the organism and the medium in which it lives and between the cells of the body and the tissue fluid that bathes them.
Answer:Diffusion takes place in the gas phase by the random motion of gas molecules.
Graham's law of diffusion (1833) states that the rate of diffusion of a gas is inversely proportional to the square root of its molecular weight (D∼MW−½). Thus, the relative rates of diffusion of CO2 and O2 are equal to √(32/44) or 0.85. Diffusion coefficients in the gas phase are Dgas ≈ 10−1 cm2/sec. In the liquid phase, diffusion rates of gases are generally 10,000 times smaller than those in gaseous environments due to the much shorter mean free path between collisions with other molecules (e.g., the solvent); thus, Dliquid ≈ 10−5 cm2/s [55]. This is not a severe handicap, however, since the distances over which gas transfer must take place in the liquid phase are generally short (about 100 times shorter than that in the gas phase).