The protein hemoglobin exhibits a sigmoidal oxygen binding curve due to
1
High oxygen affinity of individual subunits
2
Low pCO2 In tissuesp C O 2 " id="MathJax-Element-10-Frame" role="presentation" style="position: relative;" tabindex="0">p C O 2Unknown node type: span " id="MathJax-Element-1-Frame" role="presentation" style="position: relative;" tabindex="0">
3
Cooperative binding of oxygen molecules
4
A high pH in red blood cells