1. Early studies on the peptide(protein) structure 1.1 The peptide(o=c-n-h) bond was found to be shorter than the C-N bond in a simple amine and atoms attached are coplanar. 1.1.1 This was revealed by X-ray diffraction studies of amino acids and of simple dipeptides and tripeptides
1. Lipids encompass a large and diverse group of organic compounds 1.1 Lipids are broadly defined as biological molecules that are soluble in organic solvents. 1.1.1 Lipids are usually extracted from biological materials by nonpolar solvents like ether, chloroform(氯仿), benzene(苯). 1.2 The biological functions of lipids are diverse. 1.2.1 Certain lipids(e.g., triacylglycerols(三脂酰甘油), commonly called fats) serve as efficient reserves for the storage of energy
Operations used for the treatment of wastewater in which change is brought about by means of or through the application of physical forces are known as physical unit operations. Because physical unit operations were derived originally from observations of the physical world. they were the first treatment methods to be used. Today, physical unit operations, as shown on Fig. 5-1, are a major part of most wastewater
1. Proteins are extremely versatile in function and crucial in virtually all biological processes. 1.1 Almost all chemical reactions occurring in living organisms are catalyzed by enzymes. 1.1.1 Many thousands of enzymes have been discovered, each catalyzing a different kind of chemical reaction