Carbohydrat Carbohydrat BiochemistryBiochemistry

AULANNI’AMAULANNI’AMBIOCHEMISTRY LABORATORYBIOCHEMISTRY LABORATORY

BRAWIJAYA UNIVERSITYBRAWIJAYA UNIVERSITY

CarbohydratesCarbohydrates

Nature’s most abundant organic substance.Nature’s most abundant organic substance. Precursors for synthesis of all organic Precursors for synthesis of all organic

compounds in plants and animalscompounds in plants and animals Composed of C, H, and O atomsComposed of C, H, and O atoms Contain Carbon , Hydrogen and Oxygen in the Contain Carbon , Hydrogen and Oxygen in the

ratio of 1:2:1ratio of 1:2:1

CarbohydratesCarbohydrates Monomers are called monosaccharides.Monomers are called monosaccharides. Carbohydrate polymers are known as Carbohydrate polymers are known as

polysaccharides.polysaccharides.

Macromolecular StructureMacromolecular Structure MonomerMonomer

Single unit of a macromoleculeSingle unit of a macromolecule Can be linked together to form polymersCan be linked together to form polymers

MonomerMonomer Monomer Monomer

CLASSIFICATION OF CARBOHYDRATESCLASSIFICATION OF CARBOHYDRATES

MonosaccharidesMonosaccharides

OligosaccharidesOligosaccharides

PolysaccharidesPolysaccharides

Carbohydrates (cont.)Carbohydrates (cont.) MonosaccharidesMonosaccharides

““Simple sugars”Simple sugars” Monomer unit of carbohydrate groupMonomer unit of carbohydrate group Examples: Glucose, fructoseExamples: Glucose, fructose

DisaccharidesDisaccharides Composed of two monosaccharide units joined Composed of two monosaccharide units joined

togethertogether Examples: Sucrose, lactoseExamples: Sucrose, lactose

PolysaccharidesPolysaccharides Composed of multiple monosaccharide units (100s – Composed of multiple monosaccharide units (100s –

1000s)1000s) Examples: Starch, glycogen, celluloseExamples: Starch, glycogen, cellulose

MONOSACCHARIDESMONOSACCHARIDES

Polyhydroxy aldehydes or ketones which Polyhydroxy aldehydes or ketones which cannot be further hydrolysed to simpler sugarscannot be further hydrolysed to simpler sugars

Contain 3 to 10 carbon atoms, 2 or more Contain 3 to 10 carbon atoms, 2 or more hydroxyl(OH) groups and one aldehyde hydroxyl(OH) groups and one aldehyde (CHO) or one ketone (CO) group(CHO) or one ketone (CO) group

MonosacharidesMonosacharides

If n=3, triose (glyceraldehyde)If n=3, triose (glyceraldehyde)

If n=5, pentose (fructose, ribose)If n=5, pentose (fructose, ribose)

If n=6, hexose (glucose, galactose)If n=6, hexose (glucose, galactose)

Used for Energy and Building BlocksUsed for Energy and Building Blocks

MonosaccharidesMonosaccharides

Are also known as simple sugars.Are also known as simple sugars. Glucose, for example, looks like this:Glucose, for example, looks like this:

Simple SugarsSimple Sugars The most important simple sugars are glucose, The most important simple sugars are glucose,

galactose, and fructose.galactose, and fructose.

Monosaccharides (simple sugars) Monosaccharides (simple sugars)

all have the formula C6 H12 O6 all have the formula C6 H12 O6 all have a single ring structure all have a single ring structure

(glucose is an example) (glucose is an example)

Simple sugarsSimple sugars Generally made of carbon chains containing 4 Generally made of carbon chains containing 4

(tetrose), 5 (pentose), and 6 (hexose) carbons.(tetrose), 5 (pentose), and 6 (hexose) carbons. Can be drawn as a straight chain, cyclic Can be drawn as a straight chain, cyclic

compound, or a chair configuration.compound, or a chair configuration.

IsomerismIsomerism

They can exist as isomers:They can exist as isomers:

& & glucose glucose OH

OH

DisaccharidesDisaccharides Two sugars bonded together with the removal of a Two sugars bonded together with the removal of a

water molecule.water molecule.

Other common double sugars are sucrose (glucose and Other common double sugars are sucrose (glucose and fructose) and lactose (glucose and galactose).fructose) and lactose (glucose and galactose).

Disaccharides (double sugars) Disaccharides (double sugars) all have the formula C12 H22 O11 all have the formula C12 H22 O11 sucrose (table sugar) is an example sucrose (table sugar) is an example

DisaccharidesDisaccharides

Formed from two monosaccharidesFormed from two monosaccharides Joined by a glycosidic bondJoined by a glycosidic bond A condensation reaction:A condensation reaction:

glucose + glucose glucose + glucose maltose maltose glucose + galactose glucose + galactose lactose lactose glucose + fructose glucose + fructose sucrose sucrose

Dehydration Synthesis Dehydration Synthesis

Combining simple molecules to form a more Combining simple molecules to form a more complex one with the complex one with the removal of waterremoval of water ex. monosaccharide + monosaccharide ----> ex. monosaccharide + monosaccharide ---->

disaccharide + waterdisaccharide + water (C6H12O6 + C6H12O6 ----> C12H22O11 + H2O(C6H12O6 + C6H12O6 ----> C12H22O11 + H2O

Polysaccharides are formed from repeated Polysaccharides are formed from repeated dehydration syntheses of water dehydration syntheses of water They are the stored extra sugars known as starchThey are the stored extra sugars known as starch

Hydrolysis Hydrolysis

Addition of Addition of WATERWATER to a compound to to a compound to SPLITSPLIT it into smaller subunits it into smaller subunits (also called chemical digestion) (also called chemical digestion) ex. disaccharide + H2O ---> ex. disaccharide + H2O --->

monosaccharide + monosaccharidemonosaccharide + monosaccharide

C12 H22 O11 + H2 O ---> C6 H12 O6 + C6 H12 C12 H22 O11 + H2 O ---> C6 H12 O6 + C6 H12 O6O6

OLIGOSACCHARIDESOLIGOSACCHARIDES

Sugars which yield 2 to 10 monosaccharide Sugars which yield 2 to 10 monosaccharide molecules on hydrolysismolecules on hydrolysis

The monosaccharides are linked by glycosidic The monosaccharides are linked by glycosidic bondsbonds

Eg: Maltose, Lactose and SucroseEg: Maltose, Lactose and Sucrose

POLYSACCHARIDESPOLYSACCHARIDES

Non sugars giving more than 10 Non sugars giving more than 10 monosaccharide molecules on hydrolysismonosaccharide molecules on hydrolysis

High molecular weightHigh molecular weight Form colloidal substances when heated with Form colloidal substances when heated with

waterwater Several monosaccharide molecules combine Several monosaccharide molecules combine

to form polysaccharides by glycosidic linkagesto form polysaccharides by glycosidic linkages

CARBOHYDRATES - FUNCTIONSCARBOHYDRATES - FUNCTIONS

Structural component of cellsStructural component of cells Major source of energyMajor source of energy Regulation of fat metabolismRegulation of fat metabolism Osmotic and ionic regulationOsmotic and ionic regulation

PolysaccharidesPolysaccharides

Formed of three or more simple sugar units Formed of three or more simple sugar units Glycogen - animal starch stored in liver & Glycogen - animal starch stored in liver &

muscles muscles Cellulose - indigestible in humans - forms cell Cellulose - indigestible in humans - forms cell

walls walls Starches - used as energy storage Starches - used as energy storage

PolysaccharidesPolysaccharides

Made of many simple sugars linked in chains Made of many simple sugars linked in chains called polymers.called polymers.

Examples of polymers areExamples of polymers are Starch – common food storage in plants and Starch – common food storage in plants and

food for animalsfood for animals Glycogen – storage form of sugar in animalsGlycogen – storage form of sugar in animals Cellulose – main structural carbohydrate in Cellulose – main structural carbohydrate in

plantsplants

Bioorganic CompoundsBioorganic Compounds

CarbohydratesCarbohydrates Composed mostly of carbon, hydrogen, and Composed mostly of carbon, hydrogen, and

oxygenoxygen Large number of –OH groups attached to the Large number of –OH groups attached to the

carbonscarbons FunctionsFunctions

Energy source for living cellsEnergy source for living cells Certain structural components of cellsCertain structural components of cells

PolysaccharidesPolysaccharides

Polymers formed from many monosaccharidesPolymers formed from many monosaccharides Three important examples:Three important examples:

Starch Glycogen Cellulose

PolysaccharidesPolysaccharides

Polymers of several monosaccharidesPolymers of several monosaccharides Examples include: Examples include:

Starch: used by cells for energy (starch is like a Starch: used by cells for energy (starch is like a battery).battery).

Cellulose: used by plant cells for structure Cellulose: used by plant cells for structure (cellulose is like microscopic chicken wire). (cellulose is like microscopic chicken wire).

Starch looks like this:Starch looks like this:

Dehydration SynthesisDehydration Synthesis Dehydration (Dehydration (akaaka a condensation reaction) a condensation reaction)

loses water from the polymer and links loses water from the polymer and links monomers together.monomers together.

Energy is stored in the resulting bond.Energy is stored in the resulting bond.

Starch Starch

AmyloseAmylose

-glucose-glucose

1,4 glycosidic bonds1,4 glycosidic bonds

Spiral structureSpiral structure

AmylopectinAmylopectin

-glucose-glucose

1,4 and some 1,6 1,4 and some 1,6 glycosidic bondsglycosidic bonds

Branched structureBranched structure

GlycogenGlycogen

Insoluble compact store Insoluble compact store of glucose in animalsof glucose in animals

-glucose units-glucose units 1,4 and 1,6 glycosidic 1,4 and 1,6 glycosidic

bondsbonds Branched structureBranched structure

CelluloseCellulose

Structural polysaccharide in plantsStructural polysaccharide in plants -glucose-glucose 1,4 glycosidic bonds1,4 glycosidic bonds H-bonds link adjacent chainsH-bonds link adjacent chains

O

O

O

O

O

FUNCTIONS OF POLYSACCHARIDES:FUNCTIONS OF POLYSACCHARIDES:

a number of monosaccharides joined together a number of monosaccharides joined together eg. Starch, a polymer of glucose, with formula eg. Starch, a polymer of glucose, with formula (C(C66HH1010OO55))nn eg. Glycogen, same molecular eg. Glycogen, same molecular

formula--gives glucose when hydrolised, formula--gives glucose when hydrolised, stored in liver and muscles as a reserve of stored in liver and muscles as a reserve of carbohydrates. carbohydrates.

From monomers to polymersFrom monomers to polymers

HydrolysisHydrolysis

Hydrolysis adds water Hydrolysis adds water to the chemical bond to the chemical bond linking linking macromolecules.macromolecules.

This results in the This results in the breakdown of the breakdown of the polymer and the polymer and the release of energy.release of energy.

CelluloseCellulose

Cellulose productsCellulose products

Secondary metabolitesSecondary metabolites

Produced in small amountsProduced in small amounts Can be very complex Can be very complex

(chemically)(chemically)

Why do plants produce secondary Why do plants produce secondary metabolites?metabolites?

AttractantsAttractants

Why do plants produce secondary Why do plants produce secondary metabolites?metabolites?

Deter predatorsDeter predators

Secondary metabolites as Secondary metabolites as chemoprotectantschemoprotectants

Saponins and fungal resistance avenicinavenicin

Cotton produces gossypolCotton produces gossypol

trichomestrichomes

Phytoecdysones promote moltingPhytoecdysones promote molting

Thank you!Thank you!