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Lesson today Protein. Teacher : Isroli Laboratory : Animal Physiology and Biochemistry Faculty : Animal Agriculture Diponegoro University. Biological Functions of Proteins. Principal organic chemical constituents of body organs and soft tissues Enormous functional diversity
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Lesson todayProtein Teacher : Isroli Laboratory : Animal Physiology and Biochemistry Faculty : Animal Agriculture Diponegoro University
Biological Functions of Proteins • Principal organic chemical constituents of body organs and soft tissues • Enormous functional diversity • Cell membrane structure and function • Enzymes • Hormones and other chemical messengers • Immune factors (antibodies) • Fluid balance • Acid-base balance • Transport • Source of energy and glucose
The Structure of Amino Acids NH2 amino group, COOH carboxyl group, R – side chain group can be a series of functional groups
Amino Acids • The monomer unit of proteins • R is the side chain. • One of 20 different chemical compounds • Some R-groups are acid (other alkali) • Some R-groups are water soluble (others are not) Chiral carbon (L-series)
Classification Structure Net charge Polarity Essentiality Neutral Aliphatic Aromatic Sulfur Acidic Basic Heterocyclic Classification of Amino Acids
Essentiality • Essential • Amino acids not synthesize in sufficient amounts in the animal body • Required in the diet • Nonessential • Adequately synthesized in the tissue • No specific requirement • Vary by species
Arginine Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine Proline Taurine Essential Amino Acids
Leucine L, Leu Lysine K, Lys Methionine M, Met Phenylalanine F, Phe Proline P, Pro Serine S, Ser Threonine T, Thr Tryptophan W, Trp Tyrosine Y, Tyr Valine V, Val Abbreviations and Codes Alanine A, Ala Arginine R, Arg Asparagine N, Asn Aspartic acid D, Asp Cysteine C, Cys Glutamine Q, Gln Glutamic Acid E, Glu Glycine G, Gly Histidine H, His Isoleucine I, Ile
Chung-San line Northwest line Amino Acid Subway Map -C- -C-C-C-N-C-N N+ = N Trp W Arg R -C- -OH Tyr Y Lys K Asn N Gln Q -C- His H Phe F Asp D Glu E -C-C C N N+ Gly G Ala A Val V Ile I Leu L A C C -C C -C-C-C C -C-C-C C C C HN C-COOH a Ser S Cys C -C-C OH Thr T Met M Pro P Non-polar Polar Aromatic This is NOT a metabolic pathway Basic Nan-Kan line -C-CONH2 -C-C-CONH2 Amide -C-C-C-C-NH3+ Acidic -C-COOH -C-C-COOH Aliphatic Central line -H -CH3 -C-OH -C-SH Circular line South line Juang RH (2004) BCbasics -C-C-S-C Imino, Circular Hydroxy Sulfur
Classification of Amino Acids by Polarity Acidic Neutral Basic Asp Asn Arg Ser POLAR Tyr His Cys Gln Thr Lys Glu Gly Ala Ile Phe Trp NON- POLAR Met Val Leu Pro Polar (hydrophilic) or non-polar (hydrophobic), it is the bases of the amino acid properties. Juang RH (2003) Biochemistry
TUGASTulis structur 20 asam amino berdasarkan klasifikasi berikut ini • A.a. rantai samping alifatik a) glisin b) alanin c) valin 2. A.a. rantai samping hidroksil a) serin b) treonin 3. A.a. rantai samping belerang a) sistein b) metionin
4. A.a. rantai samping karboksil a) aspartic acid b) asparagin c) glutamic acid d) glutamin 5. A.a. rantai samping basa a) arginin b) histidin c) lisin d) hidroksilisin
6. A.a. rantai samping cincin aromatik a) tirosin b) fenil alanin c) tritofan 7. Asam imino a) prolin b) hidroksiprolin
Amino Acid (AA)-Protein Peptides (from the Greek πεπτος, "digestible"), are formed through condensation of amino acids through peptide bonds. Amino acids: basic unit Peptides: amino acid chain, containing 2 or more AA. Polypeptides: containing less than 50 AA. Protein: > 50 AA.
The Peptide Bond • A peptide bond is an amide bond between the carboxyl group of one amino acid and the amino group of the next amino acid O CH3 O +||+| || H3N—CH2—C—O– + H3N—CH—C—O– O H CH3 O +|||| || H3N—CH2—C—N—CH—C—O– + H2O peptide bond
Peptide Bonds Amino acids Water
Two cysteine molecules under oxidizing conditions Intermolecular or intramolecular cross-link Disulfide Bonds
Side chain Amino acid R H H R H O H O N N Backbone N N O H O H H R H R H R H R H O H-bond H O N N N N O O H H H R H R Protein Structures Proteins consist of a long chain of amino acids, the primary structure Gly Leu Ser Pro