Chapter 3 Protein Structures
Chapter 3 Protein Structures
Like the Greek sea god Proteus,who coud assume different forms.protelns act throu changesnon Proteins (from theGreek Protelos,Meaning "primary")are the primary agents of biologlcal fimction"Proteus,Old Man of the Sea Roman period masaic.from Thessalontka. Ist cntury A.D.Natlonal Archoeological Museum, Athens Anclent Art andd Architeture Collection Ld/Bridgeman An Library.London/New York)
Proteins are a diverse and abundant class of biomolecules,constituting more than 50%of the dry weight of cells.This diversity and abundance reflect the central role of proteins in virtually all aspects of cell structure and function.An extraordinary diversity of cellular activity is possible only because of the versatility inherent in proteins,each of which is specifically tailored to its biological role
Proteins are a diverse and abundant class of biomolecules, constituting more than 50% of the dry weight of cells. This diversity and abundance reflect the central role of proteins in virtually all aspects of cell structure and function. An extraordinary diversity of cellular activity is possible only because of the versatility inherent in proteins, each of which is specifically tailored to its biological role
Proteins have diverse functions: >Catalysts(Enzymes) >Provide structural rigidity >Control transport across membranes >Sensors and switches >Cause motion >Control gene function
Proteins have diverse functions: ➢Catalysts (Enzymes) ➢Provide structural rigidity ➢Control transport across membranes ➢Sensors and switches ➢Cause motion ➢Control gene function
Protein structure determines function >Proteins are single,unbranched chains of amino acid monomers >There are 20 different amino acids >A protein's amino acid sequence determines its three- dimensional structure(conformation) >In turn,a protein's structure determines the function of that protein >Four levels of structure determine the shape of proteins
Protein structure determines function ➢ Proteins are single, unbranched chains of amino acid monomers ➢ There are 20 different amino acids ➢ A protein’s amino acid sequence determines its threedimensional structure (conformation) ➢ In turn, a protein’s structure determines the function of that protein ➢ Four levels of structure determine the shape of proteins