1 protein & enzyme structure & function

1. 1 protein & enzyme structure & function (1) amino acid & peptide 1) amino acid

2. A、Biomedical importance • 10 essential amino acids • perform a multitude of structure,hormone,catalitic functions essential for life.

3. • several comparatively rare genetic disease of amino acid catabolism • amino acid urines • some intracellular functions

4. B 、properties of amino acid • the genetic code specifies 20 L--amino acids • additional amino acid occur in specific proteins

5. • only L--amino acids occur in protein • COOH • NH2 C H • R

7. • mammals contain certain free D-amino acid • amino acid may have positive, negative, or zero net charge

8. (1)zwitterions NH 3+ O - R O

9. (2) isoelectric pH (pI) • H+ H+ • R-CH-COO- R-CH-COO- R-CH-COOH • 0H 0H • NH2 NH3+ NH3+

10. • the classification of amino acid by R group (1) hydrophobic & hydrophilic (2) acidic & basic (3) aromatic & aliphatic

12. • the  -R group determine the properties of individual amino acid glycine, aliphatic R group, charged R group, alcohol group, thioalcohol group

13. • The ultraviolet absorption

15. • various techniques separate amino acids Chromatography electropheresis

18. • functional groups dictate the chemical reactions of amino acid the most important reaction of amino acids is peptide bond formation

19. 2) peptides A biomedical importance • Hormone • Nervous system • antibiotics

20. B L--amino acidslinked by peptide bonds form peptide • peptide bond

21. The formation of peptide bond the peptide bond has partial double-bond character

26. • peptide are chain of amino acid • peptide can contain unusual amino acid

30. (2) The structure of protein primary structure three dimensional structure

31. • the three dimensional structure of a protein is unique

32. • the function of a protein depends upon itsthree dimensional structure

33. • three dimensional structure means conformation

34. • Configuration & conformation

35. 1) The primary structure • definition • linkage bond • importance • example

37. 2) The secondary structure of protein • definition • types

38. a. -helix structure • the basic characteristics

42. b. -helix • the basic characteristics

44.  –pleated sheet • structure • the basic characteristics

47. c.  -turn • the basic characteristics

49. d. Random coin • the basic characteristics

50. 3) Two addition structural levels intermediate between secondary & tertiary structure • Super secondary structure • domain