Explain how oxygen is loaded, transported and unloaded in red blood cells

Haemoglobin is a molecule in red blood cells with a high affinity for oxygen. It consists of 4 haem groups, each of which associate with one oxygen molecule at high pO2, typically in the lungs. Haemoglobin dissociates from oxygen in respiring tissues, where there is a low pO2. Unloading of oxygen is linked to a higher carbon dioxide concentration.

Related Biology A Level answers

All answers ▸

Describe the synaptic transmission of a nerve impulse


A plant community on an extinct volcano displays the process of succession. Explain why there would be very few species at the end of the eruptive life cycle of the volcano and why rate of new species introduction would rapidly increase afterwards.


How is mitosis different from meiosis?


Formation of phosphodiester bond