Course Project = Algal Lipid Production Decide which algae to study
description
Transcript of Course Project = Algal Lipid Production Decide which algae to study
![Page 1: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/1.jpg)
Course Project = Algal Lipid Production1)Decide which algae to study
http://www.cbs.umn.edu/lab/wackett/links/oil2)Learn more about cell walls and lipid synthesis3)Design some experiments4)See where they lead us
![Page 2: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/2.jpg)
Course Project = Algal Lipid Production1)Decide which algae to study
http://www.cbs.umn.edu/lab/wackett/links/oilNext assignment: each pick an alga and product and convince the group in 5-10 minutes why your choice is best. Next Wed?
![Page 3: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/3.jpg)
Potential experiments1.Effects of environment on lipid production• pCO2
• Temperature• Light quantity• Light quality = color(s)• Nutrition• Adding acetate?
2. Effects of environment on cell walls
![Page 4: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/4.jpg)
Potential experiments1.Effects of environment on lipid production• pCO2
• Temperature• Light quantity• Light quality = color(s)• Nutrition
2. Effects of environment on cell walls3. Effects of inhibitors on cell walls
![Page 5: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/5.jpg)
Lipid metabolismUnique aspects in plants1) Make fatty acids in plastids2) large amounts of galactolipids3) Oleosomes: oil-storing organelles with only outer leaflet
![Page 6: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/6.jpg)
Plant GrowthSize & shape depends on cell # & cell size
![Page 7: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/7.jpg)
Plant GrowthSize & shape depends on cell # & cell sizeDecide when,where and which way to divide
![Page 8: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/8.jpg)
Plant GrowthSize & shape depends on cell # & cell sizeDecide which way to divide & which way to elongate• Periclinal = perpendicular to surface
![Page 9: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/9.jpg)
Plant GrowthSize & shape depends on cell # & cell sizeDecide which way to divide & which way to elongate• Periclinal = perpendicular to surface: get longer
![Page 10: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/10.jpg)
Plant GrowthSize & shape depends on cell # & cell sizeDecide which way to divide & which way to elongate• Periclinal = perpendicular to surface: get longer• Anticlinal = parallel to surface
![Page 11: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/11.jpg)
Plant GrowthSize & shape depends on cell # & cell sizeDecide which way to divide & which way to elongate• Periclinal = perpendicular to surface: get longer• Anticlinal = parallel to surface: add more layers
![Page 12: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/12.jpg)
Plant GrowthDecide which way to divide & which way to elongate• Periclinal = perpendicular to surface: get longer• Anticlinal = parallel to surface: add more layersNow must decide which way to elongate
![Page 13: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/13.jpg)
Plant GrowthDecide which way to divide & which way to elongate• Periclinal = perpendicular to surface: get longer• Anticlinal = parallel to surface: add more layersNow must decide which way to elongate: which walls to
stretch
![Page 14: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/14.jpg)
Plant Cell Walls and GrowthCarbohydrate barriersurrounding cell• Protects & gives cell shape
![Page 15: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/15.jpg)
Plant Cell Walls and GrowthCarbohydrate barriersurrounding cell• Protects & gives cell shape• 1˚ wall made first•mainly cellulose•Can stretch!
![Page 16: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/16.jpg)
Plant Cell Walls and GrowthCarbohydrate barriersurrounding cell• Protects & gives cell shape• 1˚ wall made first•mainly cellulose•Can stretch!
• 2˚ wall made after growth stops•Lignins make it tough
![Page 17: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/17.jpg)
Plant Cell Walls and Growth• 1˚ wall made first•mainly cellulose•Can stretch! Control elongation by controlling orientation of cell wall fibers as wall is made
![Page 18: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/18.jpg)
Plant Cell Walls and Growth• 1˚ wall made first•mainly cellulose•Can stretch! Control elongation by controlling orientation of cell wall fibers as wall is made•1˚ walls = 25% cellulose, 25% hemicellulose, 35% pectin, 5% protein (but highly variable)
![Page 19: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/19.jpg)
Plant Cell Walls and Growth1˚ walls = 25% cellulose, 25% hemicellulose, 35% pectin,
5% protein (but highly variable)Cellulose: ordered chains made of glucose linked 1-4
![Page 20: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/20.jpg)
Plant Cell Walls and Growth1˚ walls = 25% cellulose, 25% hemicellulose, 35% pectin,
5% protein (but highly variable)Cellulose: ordered chains made of glucose linked 1-4• Cross-link with neighbors to form strong, stable fibers
![Page 21: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/21.jpg)
Plant Cell Walls and GrowthCellulose: ordered chains made of glucose linked 1-4• Cross-link with neighbors to form strong, stable fibers• Made by enzyme embedded in the plasma membrane• Guided by cytoskeleton• Other wall chemicals are made in Golgi & secreted• Only cellulose pattern is tightly controlled
![Page 22: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/22.jpg)
Plant Cell Walls and GrowthCellulose pattern is tightly controlled• 6 CES enzymes form a “rosette”: each makes 6 chains
-> 36/fiber
![Page 23: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/23.jpg)
Plant Cell Walls and GrowthCellulose pattern is tightly controlled• 6 CES enzymes form a “rosette”: each makes 6 chains
-> 36/fiber• Rosettes are guided by microtubules
![Page 24: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/24.jpg)
Plant Cell Walls and GrowthCellulose pattern is tightly controlled• 6 CES enzymes form a “rosette”: each makes 6 chains • Rosettes are guided by microtubules• Deposition pattern determines direction of elongation
![Page 25: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/25.jpg)
Plant Cell Walls and GrowthCellulose pattern is tightly controlled• Deposition pattern determines direction of elongation• New fibers are perpendicular to growth direction, yet
fibers form a mesh
![Page 26: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/26.jpg)
Plant Cell Walls and GrowthNew fibers are perpendicular to growth direction, yet
fibers form a meshMultinet hypothesis: fibers reorient as cell elongatesOld fibers are anchored so gradually shift as cell grows
![Page 27: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/27.jpg)
Plant Cell Walls and GrowthNew fibers are perpendicular to growth direction, yet
fibers form a meshMultinet hypothesis: fibers reorient as cell elongatesOld fibers are anchored so gradually shift as cell growsResult = mesh
![Page 28: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/28.jpg)
Plant Cell Walls and Growth1˚ walls = 25% cellulose, 25% hemicellulose, 35% pectin,
5% protein (but highly variable)Hemicelluloses AKA cross-linking glycans: bind cellulose
![Page 29: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/29.jpg)
Plant Cell Walls and GrowthHemicelluloses AKA cross-linking glycans: bind celluloseCoat cellulose & bindneighbor
![Page 30: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/30.jpg)
Plant Cell Walls and GrowthHemicelluloses AKA cross-linking glycansCoat cellulose & bind neighborDiverse group of glucans: also linked 1-4, but may have
other sugars and components attached to C6
![Page 31: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/31.jpg)
HemicellulosesDiverse group of glucans: also linked 1-4, but may have
other sugars and components attached to C6 makes digestion more difficult
![Page 32: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/32.jpg)
HemicellulosesDiverse group of glucans: also linked 1-4, but may have
other sugars and components attached to C6makes digestion more difficultAssembled in Golgi
![Page 33: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/33.jpg)
Plant Cell Walls and GrowthHemicelluloses AKA cross-linking glycansA diverse group of glucans also linked 1-4, but may
have other sugars and components attached to C6makes digestion more difficultAssembled in GolgiSecreted cf woven
![Page 34: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/34.jpg)
Plant Cell Walls and Growth1˚ walls = 25% cellulose, 25% hemicellulose, 35% pectin,
5% protein (but highly variable)Pectins: fill space between cellulose-hemicellulose fibers
![Page 35: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/35.jpg)
PectinsPectins: fill space between cellulose-hemicellulose fibersForm gel that determines cell wall porosity(& makes jam)
![Page 36: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/36.jpg)
PectinsPectins: fill space between cellulose-hemicellulose fibersForm gel that determines cell wall porosity (& makes jam)Acidic, so also modulate pH & bind polars
![Page 37: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/37.jpg)
PectinsPectins: fill space between cellulose-hemicellulose fibersForm gel that determines cell wall porosity (& makes jam)Acidic, so also modulate pH & bind polarsBackbone is 1-4 linked galacturonic acid
![Page 38: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/38.jpg)
PectinsBackbone is 1-4 linked galacturonic acidHave complex sugar side-chains, vary by spp.
![Page 39: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/39.jpg)
PectinsBackbone is 1-4 linked galacturonic acidHave complex sugar side-chains, vary by spp.
![Page 40: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/40.jpg)
Plant Cell Walls and GrowthAlso 4 main multigenic families of structural proteins
![Page 41: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/41.jpg)
Plant Cell Walls and GrowthAlso 4 main multigenic families of structural proteinsAmounts vary between cell types & conditions
![Page 42: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/42.jpg)
Plant Cell Walls and GrowthAlso 4 main multigenic families of structural proteinsAmounts vary between cell types & conditions1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)• Proline changed to hydroxyproline in Golgi
![Page 43: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/43.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)• Proline changed to hydroxyproline in Golgi• Highly glycosylated: helps bind CH2O
![Page 44: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/44.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)• Proline changed to hydroxyproline in Golgi• Highly glycosylated: helps bind CH2O• Common in cambium, phloem
![Page 45: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/45.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)• Proline changed to hydroxyproline in Golgi• Highly glycosylated: helps bind CH2O• Common in cambium, phloem• Help lock the wall after growth ceases
![Page 46: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/46.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)• Proline changed to hydroxyproline in Golgi• Highly glycosylated: helps bind CH2O• Common in cambium, phloem• Help lock the wall after growth ceases• Induced by wounding2. PRP: proline-rich proteins
![Page 47: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/47.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins• Low glycosylation = little interaction with CH2O
![Page 48: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/48.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins• Low glycosylation = little interaction with CH2O• Common in xylem, fibers, cortex
![Page 49: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/49.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins• Low glycosylation = little interaction with CH2O• Common in xylem, fibers, cortex• May help lock HRGPs together
![Page 50: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/50.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins• Low glycosylation = little interaction with CH2O• Common in xylem, fibers, cortex• May help lock HRGPs together3. GRP: Glycine-rich proteins• No glycosylation = little interaction with CH2O
![Page 51: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/51.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins• Low glycosylation = little interaction with CH2O• Common in xylem, fibers, cortex• May help lock HRGPs together3. GRP: Glycine-rich proteins• No glycosylation = little interaction with CH2O• Common in xylem
![Page 52: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/52.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins• Low glycosylation = little interaction with CH2O• Common in xylem, fibers, cortex• May help lock HRGPs together3. GRP: Glycine-rich proteins• No glycosylation = little interaction with CH2O• Common in xylem• May help lock HRGPs & PRPs together
![Page 53: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/53.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins3. GRP: Glycine-rich proteins• No glycosylation = little interaction with CH2O• Common in xylem• May help lock HRGPs & PRPs together4. Arabinogalactan proteins
![Page 54: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/54.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins3. GRP: Glycine-rich proteins4. Arabinogalactan proteins• Highly glycosylated: helps bind CH2O
![Page 55: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/55.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins3. GRP: Glycine-rich proteins4. Arabinogalactan proteins• Highly glycosylated: helps bind CH2O• Anchored to PM by GPI
![Page 56: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/56.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins3. GRP: Glycine-rich proteins4. Arabinogalactan proteins• Highly glycosylated: helps bind CH2O• Anchored to PM by GPI• Help cell adhesion and cell signaling
![Page 57: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/57.jpg)
Plant Cell Wall Proteins1. HRGP: hydroxyproline-rich glycoproteins (eg extensin)2. PRP: proline-rich proteins3. GRP: Glycine-rich proteins4. Arabinogalactan proteins• Highly glycosylated: helps bind CH2O• Anchored to PM by GPI• Help cell adhesion and cell signaling5. Also many enzymes involved in cell wall synthesis and
loosening
![Page 58: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/58.jpg)
Plant Cell Walls and GrowthAlso many enzymes involved in cell wall synthesis and
looseningAs growth stops, start making lignins & linking HGRP
![Page 59: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/59.jpg)
Plant Cell Walls and GrowthAs growth stops, start depositing lignins & linking HGRPLignins = polyphenolic macromolecules: 2nd most
abundant on earth (after cellulose)
![Page 60: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/60.jpg)
Plant Cell Walls and GrowthLignins = polyphenolic macromolecules: 2nd most
abundant on earth (after cellulose)Bond hemicellulose: solidify & protect cell wall (nature’s
cement): very difficult to digest
![Page 61: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/61.jpg)
Plant Cell Walls and GrowthLignins = polyphenolic macromolecules: 2nd most
abundant on earth (after cellulose) Bond hemicellulose: solidify & protect cell wall (nature’s
cement): very difficult to digestMonomers are made in cytoplasm & secreted
![Page 62: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/62.jpg)
Plant Cell Walls and GrowthMonomers are made in cytoplasm & secretedPeroxidase & laccase in cell wall create radicals that
polymerise non-enzymatically
![Page 63: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/63.jpg)
Plant Cell Walls and GrowthMonomers are made in cytoplasm & secretedPeroxidase & laccase in cell wall create radicals that
polymerise non-enzymatically
![Page 64: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/64.jpg)
Plant Cell Walls and GrowthPeroxidase & laccase in cell wall create radicals that
polymerise non-enzymaticallyVery difficult to digest, yet major plant component!
![Page 65: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/65.jpg)
Plant Cell Walls and GrowthAs growth stops, start depositing lignins & linking HGRPSolidify & protect cell wall: very difficult to digestElongation precedes lignification
![Page 66: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/66.jpg)
Plant Cell Walls and GrowthAs growth stops, start depositing lignins & linking HGRPSolidify & protect cell wall: very difficult to digestElongation precedes lignificationRequires loosening the bonds joining the cell wall
![Page 67: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/67.jpg)
Plant Cell Walls and GrowthElongation precedes lignificationRequires loosening the bonds joining the cell wallCan’t loosen too much or cell will burst
![Page 68: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/68.jpg)
Plant Cell Walls and GrowthElongation precedes lignificationRequires loosening the bonds joining the cell wallCan’t loosen too much or cell will burstMust coordinate with cell wall synthesis so wall stays same
![Page 69: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/69.jpg)
Plant Cell Walls and GrowthElongation: loosening the bonds joining the cell wallCan’t loosen too much or cell will burstMust coordinate with cell wall synthesis so wall stays sameMust weaken crosslinks joining cellulose fibers
![Page 70: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/70.jpg)
Plant Cell Walls and GrowthMust weaken crosslinks joining cellulose fibersTurgor pressure then makes cells expand
![Page 71: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/71.jpg)
Plant Cell Walls and GrowthMust weaken crosslinks joining cellulose fibersTurgor pressure then makes cells expand• Lower pH: many studies show that lower pH is
sufficient for cell elongation
![Page 72: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/72.jpg)
Plant Cell Walls and GrowthMust weaken crosslinks joining cellulose fibers• Lower pH: many studies show that lower pH is
sufficient for cell elongationAcid growth hypothesis: Growth regulators cause
elongation by activating H+ pump
![Page 73: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/73.jpg)
Plant Cell Walls and GrowthAcid growth hypothesis: Growth regulators cause
elongation by activating H+ pump• Inhibitors of H+ pump stop elongation• But: Cosgrove isolated proteins that loosen cell wall• Test protein extracts
to see if wall loosens
![Page 74: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/74.jpg)
Plant Cell Walls and GrowthAcid growth hypothesis: Growth regulators cause
elongation by activating H+ pump• But: Cosgrove isolated proteins that loosen cell wall• Test protein extracts to see if wall loosens• Identified expansin proteins that enhance acid growth
![Page 75: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/75.jpg)
Plant Cell Walls and GrowthAcid growth hypothesis: Growth regulators cause
elongation by activating H+ pump• But: Cosgrove isolated proteins that loosen cell wall• Test protein extracts to see if wall loosens• Identified expansin proteins that enhance acid growth• Still don’t know how they work!
![Page 76: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/76.jpg)
Plant Cell Walls and Growth• Identified expansin proteins that enhance acid growth• Still don’t know how they work! • Best bet, loosen Hemicellulose/cellulose bonds
![Page 77: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/77.jpg)
Plant Cell Walls and GrowthAlso have endoglucanases and transglucanases that cut &
reorganize hemicellulose & pectin
![Page 78: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/78.jpg)
Plant Cell Walls and GrowthAlso have endoglucanases and transglucanases that cut &
reorganize hemicellulose & pectin XET (xyloglucan endotransglucosylase) is best-known
![Page 79: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/79.jpg)
Plant Cell Walls and GrowthAlso have endoglucanases and transglucanases that cut &
reorganize hemicellulose & pectin XET (xyloglucan endotransglucosylase) is best-knownCuts & rejoins hemicellulose in new ways
![Page 80: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/80.jpg)
Plant Cell Walls and GrowthXET is best-knownCuts & rejoins hemicellulose in new waysExpansins & XET catalyse cell wall creepage
![Page 81: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/81.jpg)
Plant Cell Walls and GrowthXET is best-knownCuts & rejoins hemicellulose in new waysExpansins & XET catalyse cell wall creepageUpdated acid growth hypothesis: main function of
lowering pH is activating expansins and glucanases
![Page 82: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/82.jpg)
Plant Cell Walls and GrowthUpdated acid growth hypothesis: main function of
lowering pH is activating expansins and glucanasesCoordinated with synthesis of new cell wall to keep
thickness constant
![Page 83: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/83.jpg)
Plant Cell Walls and SignalingPathogens must digest cell wall to enter plant
![Page 84: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/84.jpg)
Plant Cell Walls and SignalingPathogens must digest cell wall to enter plantRelease cell wall fragments
![Page 85: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/85.jpg)
Plant Cell Walls and SignalingPathogens must digest cell wall to enter plantRelease cell wall fragmentsMany oligosaccharides signal”HELP!”
![Page 86: Course Project = Algal Lipid Production Decide which algae to study](https://reader035.fdocuments.net/reader035/viewer/2022062500/5681554b550346895dc3193d/html5/thumbnails/86.jpg)
Plant Cell Walls and SignalingPathogens must digest cell wall to enter plantRelease cell wall fragmentsMany oligosaccharides signal”HELP!”Elicit plant defense responses