Chapter 5 Amino Acids, Peptides, and Proteins 0. GeneralIntroduction Proteins are polymers(多聚体) of amino acids. 20 amino acids(l ) 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 enzymes酶, hormones(激素荷尔蒙, antibodies(抗体) transporters(转运蛋 白, muscle(肌肉) lens protein of eyes(眼睛晶状体), spider webs(蜘蛛 网) rhinoceros horn(犀牛角 antibiotics(抗生素) mushroom poisons(蘑菇毒素)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. - helix,  sheets, globular, complexes, denaturation and folding. Proteins have widely diverse forms and functions. -enzymes(酶), hormones(激素,荷尔蒙), antibodies(抗体),transporters(转运蛋 白),muscle(肌肉),lens protein of eyes(眼睛晶状体), spider webs(蜘蛛 网),rhinoceros horn(犀牛角),antibiotics(抗生素),mushroom poisons(蘑菇毒素). 0. General Introduction Chapter 5 Amino Acids, Peptides, and Proteins