Vitamins are organic chemicals required by the body in trace amounts but which cannot be synthesized by the body. The vitamins required for growth and maintenance of health differ between species; compounds regarded as vitamins for one species may be synthesized at adequate rates by other species. For example, only primates and the guinea-pig require ascorbic acid (vitamin C; section 6.4) from their diet; other species possess the enzyme gluconolactone oxidase which is necessary for the synthesis of vitamin C from D-glucose or D-galactose
脂质的构成、功能及分析 The composition, function and analysis of lipids 脂质的消化与吸收 Digestion and Absorption of Lipids 甘油三酯的代谢 Metabolism of Triglyceride 磷脂的代谢 Metabolism of Phospholipid 胆固醇代谢 Metabolism of Cholesterol 血浆脂蛋白代谢 Metabolism of Lipoprotein
4.7.I Occurrence and microheterogeneity B-Lactoglobulin is a major protein in bovine milk, representing about 50% of total whey protein and 12% of the total protein of milk. It was among the first proteins to be crystallized, and since crystallizability was long considered to be a good criterion of homogeneity, B-Ig, which is a typical