The Bohr effect refers to the observation that carbon dioxide (CO2) decreases the affinity of hemoglobin (HbA) for oxygen (O2) (Rossi-Bernardi & Roughton 1967, Kwant et al. 1988, Dash & Bassingthwaighte 2010). The Bohr effect has two components: protonation of histidines in HbA (Chatake et al. 2007, Kovalevsky et al. 2010, Fang et al. 1999) and chemical reaction (carbamation) of the N-terminal valines of HbA by CO2 (Ferguson & Roughton 1934, Forster et al. 1968, Bauer & Schroder 1972, Morrow et al. 1973, Morrow et al. 1976, Mathew et al. 1977, Acharya et al. 1994). The protons (H+) for this reaction are produced by carbonic anhydrase acting on water and CO2 to produce bicarbonate (HCO3-) and H+ (Kernohan & Roughton 1968).