Amino Acid Classifications PDF

Amino acid classifications  Prof / Ayman El Baz Professor of Medical Biochemistry & Molecular Biology Dr/ Sara El Derbaly Assistant Professor of Medical Biochemistry & Molecular Biology  By the end of this lecture, the students should be able to: 1. Descr...

Amino acid classifications  Prof / Ayman El Baz Professor of Medical Biochemistry & Molecular Biology Dr/ Sara El Derbaly Assistant Professor of Medical Biochemistry & Molecular Biology  By the end of this lecture, the students should be able to: 1. Describe the general structure of amino acids 2. Classify amino acids according to structural, chemical , nutritional and metabolic nature Amino acids 1. Definition 2. General Structure 3. Classification  1.Definition of amino acids Amino acids are the structural units (building blocks) of proteins. They are obtained from protein by acid , alkali or enzymatic hydrolysis. lenzymes found in SIT(gastrointestinal tract) like trypsin in stomach & pepsin At Lein pro There are 20 known amino acids (21 after adding selenocysteine aa)  2.General structure of amino acids Each α- amino acid has the following groups or chain: General structure of COOH group amino acids NH2 group Man which is characteristic Basic structure Side Chain ( R) for each amino acids. 3.Classification of Amino Acids Four Three classifications for amino acids: 3. Chemical 1 2. Nutritional. 3 Metabolic  B) A) Chemical classification of AAs Based on the number of amino and carboxylic groups Neutral AA Acidic AA Basic AA 71NH2 2 COOH 7 1 COOH 2NH2 I NH2 =ICOOH COOH > NH2 NH2 > COOH (Neutral) (carry –ve charge) (carry +ve charge) 1 1 1 2 1 2 1 1 D Glycine, alanine Serine, threonine Cysteine, cystine Acids: AHL: A: Arginine Valine, leucine, isoleucine Aspartic acid H: Histidine Phenylalanine, tyrosine, tryptophan Glutamic Acids L: Lysine  AA (AHL) As Basic Acidic & A Neutral AAs. · aliphatic AAs 5 : (All the S has & CooH , 1 NH2) Aspartic A Arginine & Alanine, valine Leucine isoleucine - dycine , -. , , (No side chain) ↓ Branched A A. Etis - Thydroxy AAs has 1 CooH , INH DoH-CH2-CH-CoH NH2 H) CH threonine - Serine 2H) - , group) wh Histidine Of (contains HO - A · Sulfur A A :. (Thio containg A-A) - Glutamic. 5. S. Cysteine cystine , methionine (H2)-CH-C00H , COOH (contain SH group) - I L NHL - Lysine · aromatic AAs) they contain of benzene group) co (CH)) CH - - Phenylalanine , Tyrosine , Tryptophan 2 CH CH-COOH NH2 HL CH-CoH a H C wil +2 Phenylalana 1 NHL 2 NH2 1 COOH  3 Imino Acid: Proline Tryptophan Arginine Hetero- 4) cyclic Histidine C) Nutritional classification of AAs 10 Essential AA Non-essential AA To They are not synthesized in the body They are synthesized in the body. They should be taken in diet They are not essential to be taken with diet. Try This VIP Mall The rest of amino acids  1- Try: tryptophan  Glycine, alanine  2- This (threonine, histidine)  Serine, tyrosine  3- VIP( Valine, isoleucine, phenylalanine)  Cysteine, cystine  4- Mall (Methionine, arginine, leucine, lysine)  Aspartic acid, glutamic acids  Proline Arginine& histidine are semi essential AAs. Growing children require them in food. But they are not essential for the adult individuals.  Essential A A Non-Essential A A To -. - D - &. - valine , Leucine, Isoleucine (Branched) Histidine, Lysine (Basic Af) - Argine, - Threonine , Methionine (wazenb3d) - phenylalanine , Tryptophan (2 Atomatic) one Aromatic Non-essential A AsTyrosine.  D) C Metabolic classification of AAs Based on the metabolic fate: Ketogenic AA Mixed Glucogenic & Glucogenic AA ketogenic AA Metabolic fate Ketone bodies only Carbohydrate & Carbohydrate only Ketone bodies Example Only 2 AA are pure FITTT The remaining 13 AAs are pure ketogenic : glucogenic LL F: Phenylalanine L:Leucine I: Isoleucine Alanine, arginine, asparagine, L:Lysine T: Tyrosine aspartic acid, glutamic acid, - forms T: Tryptophan glutamine, glycine, cysteine, Never glucose T: Threonine histidine, methionine, proline, purely Ketogenic serin, Valin Phenylalanine Tyrosine, Tryptophans Aromatic ,  Kebgenic Mixed glugenic I I bodies) both glocd Ketone bodies (ketone ⑬ D Pheny lalanine: Aromatic The rest : Branched Leucine/Branched Alphatic Isoleucine Hydroxy Threonine : Aromatic Tryptophon Lysine/Basic Tyrosine ~ Aromatic Tyrosine Tryptophan : Aromatic AA Phenylalanine, ,  REFERENCES  Vasudevan's Textbook of Biochemistry For Medical Students, 7th Edition.  Chatterjea’s Textbook of Medical Biochemistry, 8th edition.  Lippincott’s Illustrated Reviews: Biochemistry, 8th edition 