presentase a amino acid

8/2/2019 Presentase a Amino Acid

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By :

Nindi mediartika (E1M009006)

Lutviya zun rain (E1M009018)

Mujadalah (E1M009038)

a Amino acid


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What is Amino acid?

Amino acids play central roles both as buildingblocks of proteins and as intermediates inmetabolism.

Structure :Atom C a. Called as a because adjacent with carboxyl

group ( acid).

Atom H which attached at atom C a.

Carboxyl group which attached at atom C a.

Amino group which attached at atom C a.

R group that is also attached at atom C a.


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Structure an amino acid


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Anatomy of an a-aminoacid


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R group different sidechainin each amino acid type

The different R group determines:

Structure

Measure

Charge of electric

Underwater condensationcharacter


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Standard amino acids

Amino acid compilingorganism protein is 20kinds of conceived ofstandard amino acid

Known amino acid to 21called as selenosistein (seldom be found) There isin some enzymes like

gluthatione peroxidase Selenenosistein has

genetic code: UGA
http://en.wikibooks.org/wiki/File:Molecular_structures_of_the_21_proteinogenic_amino_acids.svg


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http://en.wikibooks.org/wiki/File:Molecular_structures_of_the_21_proteinogenic_amino_acids.svg


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The Classification of amino acids

Amino acids can be classified by R Group

knowledge of the chemical properties of thestandard amino acid is central to an

understanding of bichemistry. The topic can besimplified by grouping the amino acids into fivemain classes based on the properties of their Rgroup, in particular, their polarity or tendency to

intract with water at biological pH (near pH 7.0).The polarity of the R groups varies widely, fromtotally nonpolar or hydrophobic (water insoluble)to highly polar or hyrophilic (water soluble)


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Non-polar, Aliphatic Rgroup

Has aliphatic R group

Hydrophobic

The side chain of alanine, valine, leucine, and

isoleucine tend to cluster together withinproteins, stabilizing protein structure by meansof hidrophobic interaction.

Glycine has the simplest structure.

Metheionine, one of the two sulfur-containingamino acid, has a non-polar thioeher group inits side chain.


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Non-polar, Aliphatic R group


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Aromatic R group

Relatively non polar (hidrophobic)

The hidroxyl group of tyrosine can formhydrogenbond

The important functional group in someenzymes

Tyrosine and triptophan are significantly more

polar than phenilalanine because of thetyrosine hidroxyl group and the nitrogen oftriptophan indole ring.

Aromatic amino acid can permeate [light/ray]UV 280 nm often applied to determine


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Aromatic R group


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Polar, uncharged R group

More soluble in water/more hydrophilicthey contain functional groups that formhydrogen bond with water.

Serine, threonine, cysteine, asparagine, andglutamine.

The polarity of Serine, and threonine is

contriuted by theirnhydroxil group, cysteine byits sulfhydril group, asparagine, and glutamineby their amide groups.


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Polar, uncharged R group


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Positively charged R group

Lysine, arginine, and histidine

Have basic side chain (R) Group.

Polar; hydrophilic located in proteinsurface.

Histidine is the only standard a.a having anionizable side chain with a pKa near neutraly

(has an amidazole group) Lysine amino group

Arginine guanidino group


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Positively charged R group


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Negatively charged R group

Aspartate and glutamate.

Has a second carboxyl group which ionized isfull (negative charge at pH 7.0).


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Non standard amino acids

Created by modification of standard residuesalready incorporated into a polypeptide.

Among the Non standard amino acids are 4-

hydroxyproline, a derived of proline and 5-hidroxylysine, derived from lysine.

The former is found in plant cell wall proteins,

and both are found in collagen, a fibrousprotein of connective tissues.


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Non standard amino acids


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Peptide Bond

Two a.a molecules can be covalently joinedthrought a subtituted amide linkage, termedpeptide bond, to yield a dipeptide.

3/4/5/6,. a.a are joined called oligopeptide When many a.a are joined the product called

polypepide


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Peptide Bond


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references

http://www.biology.arizona.edu/biochemistry/problem_sets / aa/aa.html

http://www.heruswn.teach-nology.com

Lehninger, A.L., Nelson, D.L., Cox, M.M. , 1993. Principlesof Biochemistry. New York :Worth Publisher.

Matta, M.K., dkk. 1996. Intoduction to General, Organic, and BiologicalChemistry. New York : D.C. Healt and Company.

Murray R.K., dkk. 2003. Biokimia Harper Edisi 25. Jakarta : PenerbitBuku Kedokteran EGC.
http://www.heruswn.teach-nology.com/http://www.heruswn.teach-nology.com/http://www.heruswn.teach-nology.com/http://www.heruswn.teach-nology.com/


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WASSALAM.......

THANK YOU FORATTENTION

presentase a amino acid

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