Experiments performed with biological systems require a buffer that will not interfere with the stability and activities of the biological components. In 1966, Norman Good and his colleagues began a series of investigations that established criteria for new zwitterionic buffers that would be optimal for experimentation with biological systems. These criteria included: a. pKa between 6 and 8 b. highly water soluble c. minimally permeable to biological membranes d. minimal effects of salt concentration e. minimal effect of temperature on pKa (Δ pKa/°C)

For each buffer below, choose the property that does not meet Good's criteria for biochemical buffers. If all of the buffer's properties satisfy the criteria for a Good's buffer, then select the last choice.