Agricultural Product

1. Agricultural Product Starch Lipid Organic waste

2. Carbohydrate producing plant • Corn • Rice • Sago • Tuber crop

3. Annual lipid producing plant

4. Perrenial lipid producing plant

5. Carbohydrate A group of organic compounds that includes sugars and related compounds Sugar • Compounds with between 3 – 7 carbon atoms having many hydroxyl (alcohol) groups and either a ketone group or an aldehyde group • A convenient source of energy • Raw material for many chemical syntheses • Water soluble

6. Sugar

7. Disaccharides Two molecules of a simple sugar linked together Sucrose Lactose Cellobiose Maltose

8. Polysaccharides Long chain of simple sugar Two main functions: • Storage • Structure

9. Storage carbohydrate • A way of storing nutrients for future needs • To cover periods when its ability to supply nutrients from photosynthesis is inadequate (during growth and regeneration) • The commonest are starches and starch like materials • It is stored at seeds or tuber

10. Starch • A mixture of two different types of molecules: 1. amylose (a long chain of glucose joint by α-1,4 linkages) 2. amylopectin (a mixture of α-1,4 links with occasionally α-1,6 branches • In general, amylopection accounts for about 70% of starch • Starch from different source vary in ratio of amylose and amylopectin

11. Plants use glyoxylate cycle to convert lipids to carbohydrates

12. Plants use glyoxylate cycle to convert lipids to carbohydrates

13. Starch synthase o Xa Glc P P P P P P P P P P P P Xb o Glc o o o o Glc Glc Glc Glc o Glc o Glc o o o o o Glc Glc Glc Glc Glc o o o o o o o o Glc o o o o o Glc Glc Glc Glc Glc Glc Glc Glc Glc Glc Glc Glc Starch biosynthesis is growing from reducing end

14. Sucrose biosynthesis • Sucrose is synthesized in cytosol by sucrose 6-phosphate synthase and sucrose 6-phosphate phosphatase.

16. Sucrose 6-phosphate synthase is also regulated G 6-P Pi Sucrose 6-phosphate synthase is regulate by phosphorylation/dephosphorylation. P Sucrose 6-phosphate synthase SPS kinase SPS PPase

17. Starch biosynthesis is regulated by ADP-glucose pyrophosphorylase

18. Lipid • Any of a group of organic compounds consisting of the fats and other substances of similar properties, insoluble in water but soluble in fats solvent and alcohol • Structurally diverse range of compounds which have 2 features in common: (1). Their presence in living organism and (2). Their general solubility in organic solvent and insolubility in water • It is characterized by the presence of fatty acid moieties and which are best described as acyl lipids

19. Plant lipid • Most plants do not store large quantities of lipids, with the exception of some oilseeds • Most lipid in plants have structural role as component of membranes and are synthesized in each cells • Plant do not transport fatty and complex lipids between their tissue • The most important plant tissues involved in lipid biosynthesis are the seeds • Seeds produce large quantities of triacylglicerols • Large agricultural and food industry has developed around the extraction and utilization of lipids from oil seeds

20. Acyl Lipid • Neutral More readily soluble in non polar hydrocarbon solvents such as light petroleum and benzene Glycerides (triacylglycerols): trihydroxy alcohol glycerols Waxes (fatty acid esters of long chain monohydroxy alcohols) • Polar Much more soluble in polar solvents like ethanol Phospholipids (diester of orthophosphoric acids) Glycolipids (one or more monosaccharide residues)

21. Acyl Lipid Structure • Major fatty acids All saturated and unsaturated monocarboxylic acids with an unbranched, even numbered carbon chain Palmitic, oleic and linoleic acids often predominate In general, saturated acids are less abundant than unsaturated acid • Minor fatty acids Two main categories: (1). Saturated and the cis-mono unsaturated acids, (2)polyunsaturated acids • Unusual fatty acids Fatty acids which have (1) non-conjugated double bonds which are trans or in an unusual position, (2). Conjugated double bond systems, (3). Allenic double bonds, (4). triple bonds, (5). Oxygen functions and (6). Branched chain

22. The Major Plant Fatty Acids

23. Glycerides • Fatty acid esters of trihydroxy alcohol • The fast majorities in nature have all 3 of glycerol hydroxy groups esterified with fatty acids and are called triglycerides (triacylglycerols) • They are the main constituents of natural fats and oil • Food reserves in seeds and/or fleshy part of fruit • Serve as carbon store in seeds required for biosynthesis processes during seed germination not as an energy store • Triacylglycerols have an advantage over carbohydrate as storage compounds due to their weight/carbon content ratio is much lower

24. Glycerides • Carbon in the seed as fat requires less than half the weight as when stored as starch • Low weight is advantageous for seed dispersal • They are deposited in oil bodies which consist of oil droplet which are surrounded by a lipid monolayer • Synthesis of glycerides occur in ER membrane • Apart from their obvious value to the plants, they are of enormous commercial importance

25. Phospholipid • Glycerophospholipids • Sphingophospholipids Glycolipid • Galactosyldiglycerides • Cerebrosides • sulpholipids

26. LIPID BIOSYNTHESIS • Fatty acid biosynthesis-basic fundamentals • Fatty acid biosynthesis-elongation and desaturation • Triacylglycerols

27. Cytosol Requires NADPH Acyl carrier protein D-isomer CO2 activation Keto  saturated Mitochondria NADH, FADH2 CoA L-isomer No CO2 Saturated  keto Fatty Acid Biosynthesis Synthesis Beta Oxidation

28. Rule Fatty acid biosynthesis is a stepwise assembly of acetyl-CoA units (mostly as malonyl-CoA) ending with palmitate (C16 saturated) 3 Phases Activation Elongation Termination

29. CH3C~SCoA O O ATP HCO3- ADP + Pi -OOC-CH2C~SCoA active carbon ACTIVATION • Acetate is the basic two-carbon unit from which fatty acids are synthesis • It must be first converted to acetyl-CoA • Acetyl-CoA is produced in large quantities from pyruvate in mitochondria of photosynthetic tissue or from glucose via the glycolitic pathway in non-photosynthetic tissue • In addition to acetyl CoA, malonyl CoA is an essential substrate for fatty acid synthesis and is produced by the carboxylation of acetyl CoA, catalyzed by Acetyl-CoA carboxylase Acetyl-CoA carboxylase

30. Acetyl-CoA CarboxylaseThe rate-controlling enzyme of FA synthesis • In Eukaryotes - 1 protein (1) Single protein, 2 identical polypeptide chains (2) Each chain Mwt = 230,000 (230 kDa) (3) Dimer inactive (4) Activated by citrate which forms filamentous form of protein that can be seen in the electron microscope

31. Acetyl-CoA Carboxylasein Plants • It is located in the chloroplasts in leaf tissue and in plastids in seeds • Unlike the enzyme in animal tissue, this is not activated by citrate, instead small changes in stromal pH or Mg or K concentration can markedly affect enzyme activity • The enzyme is also regulated by a heat stable factor found in leaves and is influenced by the ratio of ADP to ATP • High ATP levels activate the enzyme

32. Initiation CH3C~SCoA CH3C- ACP ACP + HS-CoA O O O O CH2C~S- -OOC-CH2C~S- Overall Reaction Malonyl-CoA + ACP Acyl Carrier Protein CO2 HS-CoA NOTE Malonyl-CoA carbons become new COOH end

33. Synthesis of long chain saturated fatty acids from acetyl-CoA and malonyl-CoA • It take place on a complex enzyme called fatty acid synthetase • FA synthetase 3 groups: • Type I synthetase found in animals, yeast and some bacteria • Type II synthetases occur in most bacteria and plant tissue • Type III synthetase involved in the elongation of existing fatty acid

34. -Carbon CH3C- ACP ACP ACP O O O O O H D isomer CH3C- HO H CH2C~S- = C- C~S- CH2C~S- CH3C- H CH3CH2CH2C~S- ACP Elongation Reduction NADPH -Ketoacyl-ACP reductase Dehydration -H2O  -Hydroxyacyl-ACP dehydrase NADPH Reduction Enoyl-ACP reductase

35. O Free to bind Malonyl-CoA -CH2CH2CH2C~S- ACP TERMINATION Ketoacyl ACP Synthase -KS Transfer to Malonyl-CoA Transfer to KS -S-ACP Split out CO2 CO2 When C16 stage is reached, instead of transferring to KS, the transfer is to H2O and the fatty acid is released

36. O O O CH3-CH -CH2-C-S CH3-CH2-CH2-C-S S-C-CH2-CH2-CH3 Acetyl-CoA -SH -SH S HS CoA-SH C=O KS KS KS KS KS CH2 NADP+ O C=O NADPH H+ CH3-CH=CH-C-S CH3 O O OH -C-CH3 SH Malonyl-CoA S-C-CH3 ACP O CoA-SH -C-CH2-COO- S NADP+ NADPH H+ S Fatty Acid Synthase -Ketoacyl -ACP synthase Acetyl-CoA- ACP transacylase Initiation or priming Enoyl-ACP reductase -Hydroxyacyl-ACP dehydrase H2O Malonyl-CoA- ACP transacylase -Keto-ACP synthase (condensing enzyme) CO2 -Ketoacyl -ACP reductase Elongation

37. Reduction Thioesterase palmitate release Substrate Entry AT MT DH KR ACP ER CE TE CH2 SH Translocation SH HS HS Translocation CH2 CE TE ER DH ACP KR MT AT Thioesterase palmitate release Reduction Substrate Entry

38. Acetyl-CoA + 7 malonyl-CoA + 14NADPH + 14H+ Palmitate + 7CO2 + 14NADP+ + 8 HSCoA + 6H2O 7 Acetyl-CoA + 7CO2 + 7ATP 7 malonyl-CoA +7ADP + 7Pi + 7H+ 8 Acetyl-CoA + 14NADPH + 7H+ + 7ATP Palmitate + 14NADP+ + 8 HSCoA + 6H2O + 7ADP + 7Pi Overall Reactions 7H+

39. acetyl-CoA PROBLEM: Fatty acid biosynthesis takes place in the cytosol. Acetyl-CoA is mainly in the Mitochondria How is acetyl-CoA made available to the cytosolic fatty acyl synthase? SOLUTION: Acetyl-CoA is delivered to cytosol from the mitochondria as CITRATE

40. HS-CoA COO COO CH2 CH2 HO-C-COO HO-C-COO COO C=O CH2 CH2 COO COO CH2 COO Acetyl-CoA COO CO2 HO-C-H CH2 CO2 COO COO C=O NADP+ CH3 NADPH + H+ Acetyl-CoA mitochondria Citrate lyase OAA Malate dehydrogenase NADH L-malate L-malate Malic enzyme OAA Cytosol Pyr Pyruvate

41. Post-Synthesis Modifications • C16 satd fatty acid (Palmitate) is the product • Elongation • Unsaturation • Incorporation into triacylglycerols • Incorporation into acylglycerol phosphates

42. HS-CoA R-CH2CH2CH2C~SCoA OOC-CH2C~SCoA O O CO2 CH3C~SCoA O 3 2 1 R-CH2CH2CH2CCH2C~SCoA O O NADPH NADH - H2O NADPH R-CH2CH2CH2CH2CH2C~SCoA O Elongation of Chain (two systems) Malonyl-CoA* (cytosol) Acetyl-CoA (mitochondria) Elongation systems are found in smooth ER and mitochondria

43. Desaturation Rules: The fatty acid desaturation system is in the smooth membranes of the endoplasmic reticulum There are 4 fatty acyl desaturase enzymes in mammals designated 9 , 6, 5, and 4 fatty acyl-CoA desaturase Mammals cannot incorporate a double bond beyond 9; plants can. Mammals can synthesize long chain unsaturated fatty acids using desaturation and elongation

44. 2 2 3 1 Rule: The Desaturase System requires O2 and resembles an electron transport system Cyt b5 reductase NADH Cyt b5 O2 (FAD) Saturated FA-CoA NOTE: 1.System is in ER membrane 2. Both NADH and the fatty acid contribute electrons 3. Fatty acyl desaturase is considered a mixed function oxidase

45. Fatty acid desaturation system C18-stearoly-CoA + O2 + 2H+ C189-oleyl-CoA + 2H2O Desaturase Desaturase 2 cyt b5 Fe2+ 2 cyt b5 Fe2+ Cyt b5 2H+ + cyt b5 reductase FAD cyt b5 reductase FADH2 Cyt b5 reductase NADH + H+ NAD+

46. Palmitate Desaturase 16:0 Elongase Palmitoleate Stearate 16:1(9) 18:0 Permitted transitions in mammals Desaturase Oleate 18:1(9) Essential fatty acid Desaturase Linoleate Desaturase 18:2(9,12) -Linolenate Desaturase -Linolenate 18:3(6,9,12) 18:3(9,12,15) Elongase Eicosatrienoate 20:3(8,11,14) Desaturase Other lipids Arachidonate 20:4(5,8,11,14)

47. Plant Cell Wall • They are not chemically homogeneous but composed of several different materials • They are not physically homogeneous but built up of distinct layers • The most important (90%) component of all plant cell walls of dicotyledonous are polysaccharides and about 10% is lignin, protein, water and incrusting substance • In monocot, the primary wall (the wall initially formed after the growth of cell consists of 20-30% cellulose, 25% hemicellulose, 30% pectin, and 5-10% glycoprotein; when the cells reach its final size , the secondary wall consists mainly of cellulose, is added to the primary wall • Lignin which is a complex, highly ramified polymer of phenylpropane residues

48. Polysaccharides • Micro-fibril polysaccharides • Cellulose (plant cell wall) • Chitin (fungi cell wall) • Β-1,4-mannans (green algae cell wall) • Β-1,3-xylans (green algae cell wall) • Matrix polysaccharides • Hemicellulose • Pectins

49. Cellulose • The most abundant organic substance on earth, representing about half of the total organically bound carbon • An unbranched polymer consisting of D-glucose molecules which are connected to each other by glycosidic (β1→4) linkage • Each glucose unit is rotated by 180° from its neighbor, so that very long, straight chains can be formed with a chain length of 2000-8000 glucose residues • About 150 cellulose chains are associated by inter-chain hydrogen bonds to a crystalline lattice structure known as a microfibril

50. Plant cell wall micro-fibril • Cellulose micro-fibrils consisted of about 36 chains of cellulose, a polymer of b(14)glucose • These crystalline regions are impermeable to water • Micro-fibrils have unusual highly tensile strength, very resistant to chemical and biological degradation. They are very difficult to hydrolise