Protein buffering accounts for what share of the buffering power of the blood?

1. Nearly all proteins can act as buffers, because amino acids carry both amino and carboxyl groups. 2. Those charged groups bind hydrogen ions and hydroxyl ions as conditions swing. 3. Buffering by proteins supplies two-thirds of the buffering power of the blood. 4. It also supplies most of the buffering that happens inside cells. 5. One-third is a real figure in this topic, but it is the share of red cell mass made of hemoglobin. 6. Hemoglobin is the principal protein inside red blood cells and buffers the hydrogen ions freed as carbon dioxide is converted. 7. Plasma proteins, phosphate and the bicarbonate pair make up the rest of the plasma buffering. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 26 "Fluid, Electrolyte, and Acid-Base Balance", section Protein Buffers in Blood Plasma and Cells_