Fig. 2.03

1. Fig. 2.03

2. Fig. 2.04

3. Cell Wall components • Cellulose • Other carbohydrates • Lignin (other polyphenolics) • proteins

4. Cell Wall componentsCarbohydrates • Classified by solubilities • Pectins – complex carbohydrates extracted in water using Calcium chelators • Hemicelluloses – soluble in 4M KOH • Microfibrillar components • Cellulose • Beta 1,4 mannans - algae • Beta 1,3 xylans - algae

5. Cell Wall components • Hemicelluloses • Xylans - common • Mannans – abundant in conifers • Arabinoglactans

6. Cell Wall components • Pectins • Polyuronic acids • Arabinans • Glactans

7. Cell Wall componentsNon - carbohydrate • Lignin – built of phenylpropane units that are highly cross-linked • Proteins – • Enzymes of the cell wall • Structural proteins – extensin being a very abundant protein

8. Cell Wall components • Pectins • Polyuronic acids • Arabinans • Glactans

10. Fig. 2.11

12. Box 2.1

14. Fig. 2.08

15. Fig. 2.09

16. αAraf βArap

17. Material for the rest of the class Chapter 2 – cell wall Chapter 10 – lipids Chapter 24 – secondary compounds Maybe some chapter 17 (hormones) Nothing from chapter 18

18. More Final exam information I will have questions from the last four papers I will have a page of structures – what type of molecule, how is it made, what is it used for? Somewhat cumulative but partly on material in the last section I will have a C3/C4 type question

20. The Cell wall is made of two or three structurally • independent networks • These networks interlace. • Cellulose and cross-linking glycans • Pectic polysaccarides • Structural proteins and/or phenylpropanoid network

21. Type I wall has about equal amounts of cellulose and xyloglucans Xyloglucans span the distance between microfibrils This is embedded in a pectin matrix which controls porosity

22. Fig. 2.23

26. Fig. 2.24

27. Fig. 2.25

28. Type II wall has cellulose and glucuronoarabinoxylans Some Xyloglucans are still present Less pectin Also fairly low in structural proteins but do have phenylpropanoids

29. Fig. 2.23

30. Figure 2.26 abbreviations Homogalacturonan HGA Rhamnogalacturonan RG I and RG II Hydroxyproline-rich glycoproteins HRGP Proline rich proteins PRP Glycine rich proteins GRP Arabinogalactan proteins AGP

31. Fig. 2.26

32. Fig. 2.34

33. Fig. 2.31

34. Fig. 2.09

35. Fig. 2.36

36. Fig. 2.38 Xyloglucan Endotransglycosidase

37. Fig. 10.51

38. Cutin – polymeric network of oxygenated C16 and C18 fatty acids Inelastic and hydrophobic but NOT a significant barrier to water loss – pathogen defense - yes Suberin – similar but longer fatty acids, less oxygenated And linked to phenolics – more hydrophobic than cutin Aerial surfaces covered with waxes – extremely long Chain fatty acids – prevents water loss

39. Fig. 10.55

40. Fig. 10.56

41. Fig. 10.57

42. Fig. 10.61

43. Lignin - very resistant to solubilization 40% HCl used Made of linked phenylpropane units

46. Fig. 24.52

47. Fig. 24.53 An example of a “lignan” component

48. Fig. 24.54

49. Fig. 24.58