amino-acids DESCRIPTION AND PROPERTIES .pptx

AMINO ACIDE

1. The amino acids

2. Fundamentals While their name implies that amino acids are compounds that contain an —NH 2 group and a —CO 2 H group, these groups are actually present as —NH 3 + and —CO 2 – respectively. They are classified as a , b , g , etc . amino acids according the carbon that bears the nitrogen.

3. Fundamentals amino acids play central roles both as building blocks of proteins and as intermediates in metabolism. the 20 amino acids that are found within proteins convey a vast array of chemical versatility. the precise amino acid content, and the sequence of those amino acids, of a specific protein, is determined by the sequence of the bases in the gene that encodes that protein. the chemical properties of the amino acids of proteins determine the biological activity of the protein.

4. Fundamentals proteins not only catalyze all (or most) of the reactions in living cells, they control virtually all cellular process. in addition, proteins contain within their amino acid sequences the necessary information to determine how that protein will fold into a three dimensional structure, and the stability of the resulting structure. the field of protein folding and stability has been a critically important area of research for years, and remains today one of the great unsolved mysteries. it is, however, being actively investigated, and progress is being made every day.

5. Fundamentals when proteins are digested or broken down, amino acids are left. the human body uses amino acids to make proteins to help the body: break down food grow repair body tissue perform many other body functions amino acids can also be used as a source of energy by the body.

6. Fundamentals

7. Fundamentals

8. Fundamentals

9. Fundamentals

10. Fundamentals

11. AMINO ACID Cα is at the heart of the amino acid Cα, C N and O are called backbone atoms R can be any of the 20 side chains

12. PEPTIDE BOND

13. PEPTIDE BOND We now have an oligomer Proteins are made up from 20 different amino acids String of amino acids is called “primary structure”

14. The 20 amino acids A Ala Alanine C Cys Cysteine D Asp Aspartic acid (Aspartate) E Glu Glutamic acid (Glutamate) F Phe Phenylalanine G Gly Glycine H His Histidine I Ile Isoleucine K Lys Lysine L Leu Leucine M Met Methionine N Asn Asparagine P Pro Proline Q Gln Glutamine R Arg Arginine S Ser Serine T Thr Threonine V Val Valine W Trp Tryptophan Y Tyr Tyrosine

15. The 20 amino acids The side chains, R, determine the differences in the structural and chemical properties of the 20 ‘natural’ amino acids. The 20 amino acids can, for example, be classified as follows: Hydrophobic Aliphatic Ala, Leu, Ile, Val Aromatic Phe, Tyr, Trp, (His) Hydrophilic Polar Asn, Gln Alcoholic Ser, Thr, (Tyr) Charged Arg, Lys, Asp, Glu, (His) Inbetween: Sulfur-containing Met, Cys Special Gly (no R), Pro (cyclic) Several amino acids belong in more than one category.

16. Hydrophobic

17. Aromatic

18. Hydrophilic - neutral

19. Hydrophilic - charged

20. Sulfur - containing

21. Really special

22. Cysteines are extra special

23. Amino Acids N H 3 + C O 2 – an a -amino acid that is an intermediate in the biosynthesis of ethylene + H 3 N CH 2 CH 2 C O 2 – a b -amino acid that is one of the structural units present in coenzyme A + H 3 N CH 2 CH 2 CH 2 C O 2 – a g -amino acid involved in the transmission of nerve impulses a b g

24. The 20 Key Amino Acids More than 700 amino acids occur naturally, but 20 of them are especially important. These 20 amino acids are the building blocks of proteins. All are a -amino acids. They differ in respect to the group attached to the a carbon.