the structure and function of macromolecules chapter 5 1 -- carbohydrates
TRANSCRIPT
The Structure and The Structure and Function of Function of
MacromoleculesMacromoleculesChapter 5Chapter 5
1 -- carbohydrates1 -- carbohydrates
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Macromolecules: Macromolecules: The Molecules of LifeThe Molecules of Life
Three of the four classes of life’s organic Three of the four classes of life’s organic molecules are polymers:molecules are polymers: CarbohydratesCarbohydrates ProteinsProteins Nucleic acidsNucleic acids
Lipids are not polymers, just large Lipids are not polymers, just large moleculesmolecules
Nucleic Acids and Carbohydrates -- Nucleic Acids and Carbohydrates -- both monomers & polymersboth monomers & polymers
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The Synthesis and The Synthesis and Breakdown of PolymersBreakdown of Polymers
Monomers form polymers by condensation Monomers form polymers by condensation (or dehydration) reactions(or dehydration) reactions
Polymers are disassembled to monomers Polymers are disassembled to monomers by hydrolysisby hydrolysis
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Macromolecules: Macromolecules: The Molecules of LifeThe Molecules of Life
CarbohydratesCarbohydrates Nucleic AcidsNucleic Acids ProteinsProteins LipidsLipids
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Carbohydrates – sugars Carbohydrates – sugars and polymers of sugarsand polymers of sugars
Monosaccharides -- single sugarsMonosaccharides -- single sugars Disaccharides – two sugarsDisaccharides – two sugars Oligosaccharides -- three to nine sugarsOligosaccharides -- three to nine sugars Polysaccharides -- many sugar building Polysaccharides -- many sugar building
blocksblocks
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SugarsSugars
Monosaccharides -- CHMonosaccharides -- CH22OO Glucose -- most commonGlucose -- most common Classified by location of carbonyl group Classified by location of carbonyl group
and number of carbons in skeletonand number of carbons in skeleton
LE 5-3LE 5-3Triose sugars
(C3H6O3)
GlyceraldehydeAld
ose
sK
eto
s es
Pentose sugars(C5H10O5)
Ribose
Hexose sugars(C5H12O6)
Glucose Galactose
Dihydroxyacetone
Ribulose
Fructose
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Though often drawn Though often drawn as a linear skeleton, as a linear skeleton, in aqueous solutions in aqueous solutions
they form ringsthey form rings
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glucose
12glucose
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Formed when a dehydration Formed when a dehydration reaction joins two shorter reaction joins two shorter saccharides saccharides Bond -- glycosidic linkageBond -- glycosidic linkage
Disaccharides to Disaccharides to PolysaccharidesPolysaccharides
Glucose
Maltose
Fructose Sucrose
Glucose Glucose
Dehydrationreaction in thesynthesis of maltose
Dehydrationreaction in thesynthesis of sucrose
1–4glycosidic
linkage
1–2glycosidic
linkage
Between hydroxyl in one monomer Between hydroxyl in one monomer and hydroxyl in another (e.g., 1-4 in and hydroxyl in another (e.g., 1-4 in Maltose; 1-2 in Sucrose)Maltose; 1-2 in Sucrose)
Glucose
Maltose
Fructose Sucrose
Glucose Glucose
Dehydrationreaction in thesynthesis of maltose
Dehydrationreaction in thesynthesis of sucrose
1–4glycosidic
linkage
1–2glycosidic
linkage
Glycoside LinkageGlycoside Linkage
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Glycoside LinkageGlycoside LinkageTwo ring forms: alpha (Two ring forms: alpha () and beta () and beta ())
Note: Note: glucose == galactose ….. glucose == galactose …..
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Glycoside LinkageGlycoside LinkageBetween hydroxyl in one Between hydroxyl in one
monomer and hydroxyl in monomer and hydroxyl in anotheranother Maltose (malt sugar) = glucose + Maltose (malt sugar) = glucose +
glucoseglucose Lactose (milk sugar) = glucose + Lactose (milk sugar) = glucose +
galactosegalactose
http://stefan101blog.wordpress.com/2013/03/20/glycosidic-linkage-in-carbohydrates
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Glucose
Maltose
Fructose Sucrose
Glucose Glucose
Dehydrationreaction in thesynthesis of maltose
Dehydrationreaction in thesynthesis of sucrose
1–4glycosidic
linkage
1–2glycosidic
linkage
COMMON DISACCHARIDES:COMMON DISACCHARIDES:Sucrose (table sugar) = glucose + Sucrose (table sugar) = glucose +
fructosefructoseMaltose (malt sugar) = glucose + Maltose (malt sugar) = glucose +
glucoseglucoseLactose (milk sugar) = glucose + Lactose (milk sugar) = glucose +
galactosegalactose
OligosaccharidesOligosaccharides
Typically short chains (3-9)Typically short chains (3-9) Fructose and Galactose most common Fructose and Galactose most common
monomersmonomers Often chemical markersOften chemical markers
ABO blood typeABO blood type Therapeutic to the gut floraTherapeutic to the gut flora Believed to play a part in Believed to play a part in
fertilizationfertilization
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PolysaccharPolysaccharideide
Structure and Structure and function -- function -- determined by determined by monomers and monomers and positions of positions of glycosidic glycosidic linkageslinkages
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Carbohydrates serve as Carbohydrates serve as fuel and building materialfuel and building material
SourceSource ---- cellular respiration cellular respiration Storage -- Storage -- polysaccharidespolysaccharides Structural components -- Structural components -- cell walls, cell walls,
microfibrils, chitinmicrofibrils, chitin
© 2009 W.W. Norton & Company, Inc. DISCOVER BIOLOGY 4/e
Cellular RespirationCellular Respiration and Photosynthesis and Photosynthesis
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RESPIRATIONRESPIRATION
C6H12O6 + O2 CO2 + H2O + ENERGY
ATP
686 kcal/mole (180 grams)
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Pyruvate
Glucose
CYTOSOL
No O2 presentFermentation or Anaerobic respiration
Ethanolor
lactate
Acetyl CoA
MITOCHONDRION
O2 present -- Aerobic cellular respiration
Citricacidcycle
Glycolysis …. What Glycolysis …. What next?next?
Glycolysis
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Photosynthesis Photosynthesis Summarized Summarized
6 CO2 + 12 H2O + Light energy C6H12O6 + 6 O2 + 6 H2 O
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ChloroplastChloroplast Gelatinous matrix called the stroma Contains prokaryotic ribosomes,
DNA Carbohydrate synthesis occurs in
the stroma Folded membranes called thylakoids fill the stroma and form into stacks called grana
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H2O
LIGHTREACTIONS
Chloroplast
Light
ATP
NADPH
O2
Light reactions (in the thylakoids) -- split water, release O2, produce ATP, and form NADPH
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H2O
LIGHTREACTIONS
Chloroplast
Light
ATP
NADPH
O2
NADP+
CO2
ADPP+ i
CALVINCYCLE
[CH2O](sugar)
The Calvin cycle (in the stroma) -- forms sugar from CO2, using ATP and NADPH
Respiration & Respiration & PhotosynthesisPhotosynthesis
Respiration Respiration
CC66HH1212OO66 + O + O22 CO CO22 + H + H22O + ENERGYO + ENERGY
PhotosynthesisPhotosynthesis
COCO22 + H + H22O O C C66HH1212OO66 + O + O22 + H + H22 O O
Light energy Light energy
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Storage PolysaccharidesStorage Polysaccharides
Plants store Plants store surplus starch surplus starch as granules as granules within within chloroplasts, chloroplasts, leukoplasts, leukoplasts, and other and other plastids plastids
Chloroplast Starch
1 µm
Amylose
Starch: a plant polysaccharide
Amylopectin
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Glycogen is the Glycogen is the storage storage polysaccharide polysaccharide in animalsin animals
Humans and Humans and other other vertebrates vertebrates store glycogen store glycogen mainly in liver mainly in liver and muscle and muscle cellscells
Storage PolysaccharidesStorage PolysaccharidesMitochondriaGlycogen granules
0.5 µm
Glycogen
Glycogen: an animal polysaccharide
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Structural Structural PolysaccharidesPolysaccharides
Cellulose -- plant cell wallsCellulose -- plant cell walls Chitin -- cellulose-ishChitin -- cellulose-ish
Polymers of glucose – different glycosidic Polymers of glucose – different glycosidic linkageslinkages alpha glucose – helicalalpha glucose – helical beta glucose -- straightbeta glucose -- straight
In In ββ glucose glucose -- hydrogen bonds form between strands-- hydrogen bonds form between strandsstrands group into microfibrils -- strong building strands group into microfibrils -- strong building
materials for plantsmaterials for plants
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Cellulosemolecules
Cellulose microfibrilsin a plant cell wall
Cell walls Microfibril
Plant cells
0.5 µm
Glucosemonomer
Cellulose vs StarchCellulose vs Starch
Enzymes that digest starch by Enzymes that digest starch by hydrolyzing alpha linkages can’t hydrolyzing alpha linkages can’t hydrolyze beta linkages in cellulosehydrolyze beta linkages in cellulose
Cellulose in human food -- insoluble Cellulose in human food -- insoluble fiberfiber
Some microbes use enzymes to digest Some microbes use enzymes to digest cellulosecellulose
Many herbivores, from cows to Many herbivores, from cows to termites, have symbiotic relationships termites, have symbiotic relationships with these microbeswith these microbes
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ChitinChitin
exoskeleton of arthropodsexoskeleton of arthropods primary component of cell walls in fungiprimary component of cell walls in fungi structurally – similar to cellulosestructurally – similar to cellulose functionally – similar to protein keratinfunctionally – similar to protein keratin
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SucraloseSucralose
Sucrose
SucraloseCl
Cl
Cl
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Stevia
Steviol
Stevioside
AspartameAspartame Aspartame is a methyl ester of Aspartame is a methyl ester of
aspartic acid and phenylalanine (2 aspartic acid and phenylalanine (2 amino acids).amino acids).
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SaccharineSaccharine
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