PPT-Proteins Ch 11- Amino Acids and Peptides

Unit objectives Identify amino acid classifications based on nutritional use and chemical properties of side chains Describe the primary secondary tertiary and quaternary structures of proteins. CHAPTER 3, Part 1 . Amino Acids and Peptides . To know the structure and naming of all 20 protein amino acids. To know the structure and properties of peptides and the particularly the structure of the peptide bond.. Subunits (building blocks) of peptides and proteins. Neurotransmitters. Metabolic intermediates. glutamate. γ. -. aminobutyric. acid. (GABA). Proteins are synthesized from 20 ‘standard’ . α. -amino acids. Their names have 3- and 1-letter abbreviations.. amine group. Draw. a carboxylic acid group. Join. them together to form a molecule with an amine and . a carboxylic acid . group. Amino Acids. Building blocks of proteins. Two functional groups: a carboxylic acid and a primary amine. ). Dr. . Sumbul. . Fatma. Learning outcomes. What are the amino acids?. General structure.. Classification of amino acids.. Optical properties.. Amino acid configuration.. Non-standard amino acids.. Polypeptides . are chains of amino acids linked together by condensation reactions. the main, or only, component in proteins. Some proteins are composed of only one polypeptide chain, while others are made of 2 or more. . are organic molecules that are the building block of . . proteins. .. -There is 20 . α. -amino acids commonly found in . proteins. . ( . they . have a carboxyl group and an amino group . . . 6. 6.1 Differentiate . between essential amino acids and nonessential amino acids.. 6.2 List . the functions of protein in the body.. 6.3 List . the steps for protein digestion and absorption in the body. . Each amino acid (aa) shares a common structure; i.e. an amine (NH. 2. ) group, an acid group (COOH), and a central carbon atom bonded to hydrogen and to a side chain (R).. The side chains qualify aas as acidic, basic, neutral, aromatic, and sulphur-containing amino acids.. Peptide bond formation. : . α-carboxyl group of one amino acid (with side chain R1) forms a covalent peptide bond with α-amino group of another amino acid . ( . with the side chain R2) by removal of a molecule of water. The result is : Dipeptide ( i.e. Two amino acids linked by one peptide bond). By the same way, the dipeptide can then forms a second peptide bond with a third amino acid (with side chain R3) to give . Protein. Builds and repairs body tissue. Provides some energy. There are 4 calories per gram of protein. Protein. Composed of chains of amino acids. Common Amino Acids. Alanine. Glycine. Isoleucine. Leucine. Amino Acids are the building units of proteins.. The main role of amino acids is in the synthesis of structural and functional . proteins.. The . non-essential amino acids are either derived from the. A. . Peptides. are compounds, formed of less . than . 50 . amino acids . linked together by peptide bonds.. 1.. . Dipeptide. (2 amino acids and one peptide bond).. 2.. . Tripeptide. (3 amino acids and two peptide bonds).. BSc 3. rd. year . AMINO ACIDS. C. lassification of amino acids . Classification according to nature of side chain. PREPARATION OF AMINO ACIDS. 1. Gabriel Phthalimide synthesis. 2. Strecker’s synthesis.  . Constantinos. Avraamides . 1. , . Spyridoula. . Diavoli. . 1. , Ariana Robertson . 2. , Manos Vlasiou . 1. , Elena . Mourelatou. . 1. ,. Christos Petrou . 1. , Yiannis Sarigiannis *. 1. 1. Department of Life & Health Sciences, University of Nicosia, Nicosia, Cyprus.