The oxygen-binding capacity of hemoglobin is affected by pH. The saturation curve of hemoglobin at normal physiological pH $(7.4)$ is given in figure below.

Sketch the saturation curve of hemoglobin at pH $= 7.2$ .

Explain, in terms of enzyme inhibition, the effects of protons and carbon monoxide on the saturation curve of hemoglobin.

Experiments show that our appreciation of food is based on interactions between our senses. Discuss how the different senses interact in giving us empirical knowledge about the world.