Amino Acids (1) IUA, 2012
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Amino Acids (1)Atif H. Khirelsied, Ph.D. Atif H. Khirelsied, Ph.D.Department of BiochemistryFaculty of MedicineInternational University of Africa, Khartoum, SudanAmino Acids1. Amino acids (aa) are organic acids with an amine Amino acids (aa) are organic acids with an amine group. 2. They are the "building blocks" of proteins. 3. Have a wide range of diverse biological functions. 4. There are more than 300 in nature. 4 There are more than 300 aa in nature 5. Only 20 L‐α‐amino acids ar
Transcript of Amino Acids (1) IUA, 2012
AminoAcids(1)AtifH.Khirelsied,Ph.D. Atif H. Khirelsied, Ph.D.DepartmentofBiochemistry
FacultyofMedicineInternationalUniversityofAfrica,Khartoum,Sudan
AminoAcids1. Amino acids (aa) are organic acids with an amine Aminoacids(aa)areorganicacidswithanamine group. 2. Theyarethe"buildingblocks"ofproteins. 3. Haveawiderangeofdiversebiologicalfunctions. 4. Therearemorethan300 innature. 4 There are more than 300 aa in nature 5. Only20Laminoacids arefoundinproteins.Atif Hassan Khirelsied
AminoAcids5. DAminoacidsoccurinbacteriaandpeptide antibiotics. ibi i 6. Severalotheraminoacidsarefoundinnonprotein 6 S l h i id f di i substances.
Atif Hassan Khirelsied
AminoAcidsStructure
Atypicalaminoacidhasaprimaryaminogroup,acarboxyl group,ahydrogenatomandasidechain (Rgroup)attachedtoa chiral carbon atom carbonatom.
Atif Hassan Khirelsied
AminoAcidsStructure
TheFunctionsofAminoAcids Theyarethe"buildingblocks"ofproteins. y g p Are important (essential) nutrients Areimportant(essential)nutrients. Componentsofvariousbiomoleculese.g.,serinein phospholipids.
Atif Hassan Khirelsied
TheFunctionsofAminoAcids Precursor for various biologic substances Precursorforvariousbiologicsubstances. Glucose. Heme. Purines andpyrimidines. Neurotransmitters. Hormones
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Aminoacids,isomerism &opticalactivity
Enantiomers
Allstandardaminoacidsexceptglycine andproline havechiral carbons(theC),thusexistinpairsof(D)and(L)enantiomers.
Atif Hassan Khirelsied
Aminoacidsclassifications Aminoacidscanbeclassifiedaccordingto: 1. 1 ChemicalnatureofRgroups Chemical nature of R groups 2. Solubility 3. Dietaryimportance 4. Metabolicfate
Atif Hassan Khirelsied
Aminoacids;classificationbyR-group According to the chemical nature of the side chain, Accordingtothechemicalnatureofthesidechain, aminoacidscanbeclassifiedinto:1. 1 2. 3. 3 4. 5. 6. 7. Aliphaticnonpolaraminoacids. Aliphatic nonpolar amino acids Sulfurcontainingaminoacids. Hydroxylcontainingaminoacids. H d l t i i i id Aromaticaminoacids. Acidicaminoacidsandtheiramides. Basicaminoacids. Imino acid
Atif Hassan Khirelsied
Thealiphaticnonpolaraminoacids
This class include: 1. 1 Glycine 2. Alanine 3. Valine 4. Leucine 5. Isoleucine
Atif Hassan Khirelsied
Thealiphaticnonpolaraminoacids1. 1 Glycine (Gly or G).Glycine
Is the smallest amino acid. p Has the simplest structure. Does not exist as a pair of stereoisomers
Atif Hassan Khirelsied
Thealiphaticnonpolaraminoacids2. 2 Alanine ( (Ala or A) )Alanine
Is aliphatic amino acid. Has a methyl group in the side-chain position.
Hydrophobic.Atif Hassan Khirelsied
Thealiphaticnonpolaraminoacids3. Valine, Val , (V).
4. Leucine, 4 Leucine Leu, (L).
5. Isoleucine, Ile, (I).Atif Hassan Khirelsied
Thealiphaticnonpolaraminoacids6.Methionine, Met, (M).
NOTEThealiphaticsidechainsofAla,Val,Leu,Ile&Metare nonreactive,hydrophobic.
Atif Hassan Khirelsied
Thesulphur containingaminoacids7. Cysteine Cys, (C).
Methionine Met (M)
Note Met is also an aliphatic non-polar amino acidAtif Hassan Khirelsied
Thehydroxylcontainingaminoacids8. Serine Ser, (S).
9. Threonine Thr, (T).
Tyrosine T i Tyr, (Y).Atif Hassan Khirelsied
Theacidicaminoacidsandtheiramides10. Aspartic acid Asp,(D)
11. Asparagine Asn, (N).
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Theacidicaminoacidsandtheiramides
12.Glutamic acid Glu, (E).
13. Glutamine 13 Gl t i Gln, (Q).
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Thebasicaminoacids14. 14 Araginine Arg, (R).
15. Lysine Lys, (K).
16.Histidine His, (H). His (H)Atif Hassan Khirelsied
Thearomaticaminoacids17. Phenylalanine Phe, (F).
18. 18 Tyrosine Tyr, (Y).
19. 19 Tryptophan Trp, (W).Atif Hassan Khirelsied
Theimino acid
20. Proline Pro, (P).
Thenitrogenatomissecondarilyattachedtotheside chains. chains
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Thecystine
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Aminoacidsclassificationbysolubility Twoclassesofaminoacidsbaseduponwhetherthe R groupis; Rgroup is; 1. Hydrophobic 1 H d h bi 2. Hydrophilic.
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Aminoacidclassificationbydietary importance.Someaminoacidscanbeformedfrommetabolic intermediatesinthemammaliancells,thusarenot intermediates in the mammalian cells thus are not necessarytakeninfood(Dietarynonessential) .
Otheraminoacidsmustbeobtainedfromdiet,thus theyaretermed(Dietaryessential).Atif Hassan Khirelsied
AminoacidsclassificationbymetabolicfateAminoacidscanalsobeclassifiedaccordingtothe endproductoftheircarbonskeletoncatabolisminto: p 1. 1 Gluogenic glucose producing glucoseproducing 2. Ketogenic ketones producing 3. Keto andglycogenic.
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