Revised Chapter 12, Biological Membranes: Structure, Receptors, and Solute Transport present solute transport in accordance with the current understanding, classificaon, and nomenclauter of the field. Examples of mechanisms are presented under the individual classificaons of transport mechanism. A new secon presenng the general informaon about receptors was added. ? Heme coverage is now presented along with the discussion of amino acid metabolism in Chapter 19, Amino Acid and Heme Metabolism, This new placement of the material in a chapter with an emphasis on nitrogen metabolism is common in most biochemical textbooks. ? New Chapter 26, Vitamins and Minerals consolidates material and reflects the increasing knowledge about the role of these micronutrients in other than their classical acvies.