Chapter 3 ProteinsOutlineClassification of proteinsThe basic building blocks of proteinsAmino acidsStructure of proteinsStructure and function relationships of proteinsProperties of proteinsSeparation, purification and determination ofproteins
Chapter 3 Proteins Outline u Classification of proteins u The basic building blocks of proteins—Amino acids u Structure of proteins u Structure and function relationships of proteins u Properties of proteins u Separation, purification and determination of proteins
What are proteins?Proteins are macromolecules composedof amino acids linked together throughpeptide bonds, which have a stableconformation and a certain biologicalfunction.Proteins are linear polymers聚合物 builtof monomer单体 units called amino acids
What are proteins? Proteins are macromolecules composed of amino acids linked together through peptide bonds, which have a stable conformation and a certain biological function. Proteins are linear polymers聚合物 built of monomer单体 units called amino acids
Section 1Classification of proteins1. Chemical Components of ProteinsSMajor elements: C, H, O, N.Trace elements: P, Fe, Cu, Zn, Mo, I, ..The average nitrogen content in proteins is about16%, and proteins are the major source of N inbiological systems
Section 1 Classification of proteins 1. Chemical Components of Proteins uMajor elements: C, H, O, N, S uTrace elements: P, Fe, Cu, Zn, Mo, I, . u The average nitrogen content in proteins is about 16%, and proteins are the major source of N in biological systems
Section 1Classification of proteins1. Chemical Components of ProteinsThe protein quantity can be estimated---Kjeldahldetermination（凯氏定氮法）protein in 100g sample = N per gram X 6.25 X 100
Section 1 Classification of proteins 1. Chemical Components of Proteins uThe protein quantity can be estimated-Kjeldahl determination（凯氏定氮法） uprotein in 100g sample = N per gram × 6.25 × 100
2. Protein ClassificationClassification based on the overall shape1（球状蛋白质）：Globularproteinglobular or ellipsoidal (long/short <1O), soluble inwater; including enzymes, transportors, receptorsregulators, .（纤维状蛋白质）：Fibrous proteinhighly elongated; insoluble in water; includingcollagen（胶原蛋白），elastin（弹性蛋白），α-keratin（α-角蛋白）
2. Protein Classification uClassification based on the overall shape Globular protein（球状蛋白质）: globular or ellipsoidal (long/short <10), soluble in water; including enzymes, transportors, receptors, regulators, . Fibrous protein（纤维状蛋白质）: highly elongated; insoluble in water; including collagen（胶原蛋白）, elastin（弹性蛋白）, α- keratin（α-角蛋白）,