1. General studies of the peptide bond 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. 1.1.2 The peptide (amide) bond was found to be about 1.32 A (C-N single bond, 1.49; C= double bond, 1.27), thus having partial double bond feature (should be rigid and unable to rotate freely)

1. 烷、烯、炔的结构特征与反应性 2.立体结构表示、构象与构型 3.开链烃的命名 4.烷烃化学性质 5.烯烃、炔烃化学性质 6.二烯烃化学性质

Biological Membranes and Transport Biological membranes are made of a lipid bilayer decorated with various proteins and/or carbohydrates. Membranes define the external boundaries of cells and regulate the molecular traffic across that boundary In eukaryotic cells, membranes also divide the internal space into discrete compartments to segregate processes and components

Chapter Amino Acids, Peptides, and Proteins 0. General Introduction Proteins are polymers(多聚体) of amino acids. -20 amino acids(氨基酸)→ millions of proteins with different properties and activities. Protein structures are studied at primary, secondary, tertiary and quaternary levels. -a helix, B sheets, globular, complexes, denaturation and folding. Proteins have widely diverse forms and functions

第一节 概述 第二节 氨基酸 第三节 蛋白质的一级结构 第四节 蛋白质的空间结构与功能 第五节 蛋白质的重要理化性质 第六节 蛋白质相对分子量的测定

一、填空题 1.氨基酸的等电点(pI)是指________________。 2.氨基酸在等电点时，主要以________________离子形式存在，在 pH>pI的溶液中，大部分以________________离子形式存在，在 pH