Bio E109 Module 4 Ques ons and answers updated
New 2026
Describe how the terms of the ideal gas law may affect the concentra on of a gas in solu on.
it determines what factors influence the pressure since the pressure is what's driving oxygen
into solu on;
being able to change how much pressure is above the solu on, then we can change how much
O2 is driven into the solu on;
if we want to maximie the pressure, then we lower the volume (plunger into the system like a
closed volume) drives more O2 into the solu on;
PRESSURE & VOLUME ARE FIXED
Explain how air pressure changes with a modifica on on the volume that contains a fixed
number of gas molecules.
if the volume is decreased, there is more pressure and vice versa
Define a 'par al pressure' and explain its importance for exchange.
par al pressure the propor on of pressure that's generated by one type of gas;
the par al pressure is a driving force for diffusion into a solu on;
depending on how high or how low the PP, it will wither favor diffusion into or out of the blood;
gas composi on of air favors gas exchange into the lungs
Describe how the components of blood chemistry influence the solubility of oxygen.
the solu on in which the O2 is present plays a factor if it'll favor O2 or not (ex: water tends to
hold on to CO2 be5er than it does to O2. Plasma is be5er than water in terms of obtaining O2);
the hemolglobin in the RBC contains iron that have heme groups (really good at binding to
oxygen)
Use the oxygen-dissocia on curve to explain how O2 solubility changes during exchange in the
lungs and in the cells.
at full air capacity in the lungs and capillaries, the PP is at 100 mmHg, once the blood gets
transported through the body, the O2 eventually finds its way to capillaries to cells that need it;
oxygenated blood = equilibrium with the air at 100 mmHg
Explain the func onal significance of the non-linear rela onship of the oxygen-dissocia on
curve for exchange at the cells.
, the non-linear rela onship tells us how much oxygen the cells need- liberates oxygen and gives
it to the cells- the Par al pressure increase in plasma causes the hemoglobin to bind O2
a linear rela onship- any drop in PP would cause the same libera on of O2 instead of a
libera on when the cells need it
Describe how the pH, temperature, and PCO2 affect the oxygen-dissocia on curve and why that
ma5ers for exchange.
pH- at normal levels is at a pH of 7.4 but when the body is ac ve, the curve is at pH of 7.2; the
lower pH curve also means that there is a significantly less satura on = more O2 is being
released by the blood to the cells;
blood is less saturated with lower levels of pH and higher levels of CO2/ temp
Describe the major means of CO2 transport in the blood.
exchange at cells:
1. in plasma (7%)
2. binding to Hb (23%)
3. conversion od CO2 to bicarbonate (70%)
CO2 + H2O ---> HCO3 + H+ (bicarbonate and a free H+ that lowers the blood pH)
exchange at lungs:
the bicarbonate and H+ is being turned back to CO2 and H2O
Explain the anatomical posi on of the trachea, lungs, thoracic cavity, and alveoli.
the thoracic cavity- contains the lungs and the heart
trachea- the tube that a5aches to the nose/mouth as well as the lungs
lungs- contains bronchioles
alveoli- sacs in the brochioles; capillaries that are the site of gas exchange
Describe how the diaphragm, external intercostal, and scalene muscles serve to drive
inspira on.
the diaphragm- when it's contracted, the floor in the thoracic cavity, it drops the air pressure in
the lungs and drives air into the lungs which increases the pressure
external intercostals- when the muscles contract, they expand the thoracic cavity by expanding
the ribcage and the volume
scalene muscles- rotate the ribcage forward for expansion of thoracic cavity and of the volume
Explain how the internal intercostal and abdominal muscles drive expira on.
internal intercostals- below the externals; reduce the space between the ribs = reduces the
volume contained in the ribcage
New 2026
Describe how the terms of the ideal gas law may affect the concentra on of a gas in solu on.
it determines what factors influence the pressure since the pressure is what's driving oxygen
into solu on;
being able to change how much pressure is above the solu on, then we can change how much
O2 is driven into the solu on;
if we want to maximie the pressure, then we lower the volume (plunger into the system like a
closed volume) drives more O2 into the solu on;
PRESSURE & VOLUME ARE FIXED
Explain how air pressure changes with a modifica on on the volume that contains a fixed
number of gas molecules.
if the volume is decreased, there is more pressure and vice versa
Define a 'par al pressure' and explain its importance for exchange.
par al pressure the propor on of pressure that's generated by one type of gas;
the par al pressure is a driving force for diffusion into a solu on;
depending on how high or how low the PP, it will wither favor diffusion into or out of the blood;
gas composi on of air favors gas exchange into the lungs
Describe how the components of blood chemistry influence the solubility of oxygen.
the solu on in which the O2 is present plays a factor if it'll favor O2 or not (ex: water tends to
hold on to CO2 be5er than it does to O2. Plasma is be5er than water in terms of obtaining O2);
the hemolglobin in the RBC contains iron that have heme groups (really good at binding to
oxygen)
Use the oxygen-dissocia on curve to explain how O2 solubility changes during exchange in the
lungs and in the cells.
at full air capacity in the lungs and capillaries, the PP is at 100 mmHg, once the blood gets
transported through the body, the O2 eventually finds its way to capillaries to cells that need it;
oxygenated blood = equilibrium with the air at 100 mmHg
Explain the func onal significance of the non-linear rela onship of the oxygen-dissocia on
curve for exchange at the cells.
, the non-linear rela onship tells us how much oxygen the cells need- liberates oxygen and gives
it to the cells- the Par al pressure increase in plasma causes the hemoglobin to bind O2
a linear rela onship- any drop in PP would cause the same libera on of O2 instead of a
libera on when the cells need it
Describe how the pH, temperature, and PCO2 affect the oxygen-dissocia on curve and why that
ma5ers for exchange.
pH- at normal levels is at a pH of 7.4 but when the body is ac ve, the curve is at pH of 7.2; the
lower pH curve also means that there is a significantly less satura on = more O2 is being
released by the blood to the cells;
blood is less saturated with lower levels of pH and higher levels of CO2/ temp
Describe the major means of CO2 transport in the blood.
exchange at cells:
1. in plasma (7%)
2. binding to Hb (23%)
3. conversion od CO2 to bicarbonate (70%)
CO2 + H2O ---> HCO3 + H+ (bicarbonate and a free H+ that lowers the blood pH)
exchange at lungs:
the bicarbonate and H+ is being turned back to CO2 and H2O
Explain the anatomical posi on of the trachea, lungs, thoracic cavity, and alveoli.
the thoracic cavity- contains the lungs and the heart
trachea- the tube that a5aches to the nose/mouth as well as the lungs
lungs- contains bronchioles
alveoli- sacs in the brochioles; capillaries that are the site of gas exchange
Describe how the diaphragm, external intercostal, and scalene muscles serve to drive
inspira on.
the diaphragm- when it's contracted, the floor in the thoracic cavity, it drops the air pressure in
the lungs and drives air into the lungs which increases the pressure
external intercostals- when the muscles contract, they expand the thoracic cavity by expanding
the ribcage and the volume
scalene muscles- rotate the ribcage forward for expansion of thoracic cavity and of the volume
Explain how the internal intercostal and abdominal muscles drive expira on.
internal intercostals- below the externals; reduce the space between the ribs = reduces the
volume contained in the ribcage
