Oxygen Dissociation Curve – Bohr Shift, Fetal Haemoglobin and Myoglobin
BiologyHuman & Animal PhysiologyAges 16–17
Use it with your class: students open it from a link or a QR code, with no account needed.
Next in Human & Animal Physiology
Plot the percentage saturation of haemoglobin against pO₂ and read how much oxygen is unloaded between the lungs and respiring tissue. Raise pCO₂, lower the pH or warm the tissue to see the Bohr shift, compare fetal haemoglobin, myoglobin and llama haemoglobin, and follow how CO₂ is carried in the blood.
Lesson: Transport of oxygen and carbon dioxide: the oxygen dissociation curve, the Bohr effect, fetal haemoglobin and myoglobin, the chloride shift
What it shows
Haemoglobin loads oxygen where the partial pressure of oxygen is high and unloads it where it is low, and its S-shaped dissociation curve shows how much. In respiring tissue, more carbon dioxide, a lower pH and a higher temperature shift the curve to the right, so more oxygen is released: the Bohr effect. You read saturations in the lungs and in the tissue, compare four oxygen-binding pigments, and watch how carbon dioxide travels back to the lungs. The curves use textbook P50 values and a published equation for the shift; the CO₂ transport picture is not to scale.
How to use
On Bohr shift, drag the Lungs and Tissue lines or use the pO₂ sliders, then change pCO₂, pH and temperature and press Record reading. Standard conditions and Exercising muscle set the tissue for you. On Compare pigments, move pO₂ for reading. On CO₂ transport, choose Where and press Run.
Parameters you can change
- View Bohr shift, Compare pigments, CO₂ transport
- Pigment Adult haemoglobin (HbA), Fetal haemoglobin (HbF), Myoglobin, Llama haemoglobin
- pCO₂ in the tissue 2–10 kPa
- pH follows pCO₂
- pH in the tissue 7–7.8
- Temperature in the tissue 33–43 °C
- pO₂ in the lungs 4–16 kPa
- pO₂ in the tissue 0.5–13 kPa
- pO₂ for reading 0–16 kPa
- Pressure unit kPa, mmHg
- Where Respiring tissue, Lungs
Questions to explore
- How much more oxygen does adult haemoglobin unload in an exercising muscle than in resting tissue, and why?
- At a pO₂ of 4 kPa, which pigment is most saturated, and what does that mean for where it gives up oxygen?
- Why does a higher pCO₂ in respiring tissue lead to more oxygen being released from haemoglobin?
