CarbohydratesCarbohydrates

CarbohydratesCarbohydrates

Majo r so urce o f e ne rg y.Majo r so urce o f e ne rg y. Organic co mpo unds made up o f Organic co mpo unds made up o f

CarbonCarbon, , HydrogenHydrogen and and OxygenOxygen.. Ratio o f hydro g e n and o xyg e n is 2 : 1 , Ratio o f hydro g e n and o xyg e n is 2 : 1 ,

as in wate r.as in wate r. Gene ral fo rmula : Ge ne ral fo rmula : Cx(H2O)y

Chemically carbo hydrate s are de fine d Chemically carbo hydrate s are de fine d as as polyhydroxy aldehydespolyhydroxy aldehydes o r o r ketonesketones..

Photosynthesis Photosynthesis in g re e n plants is the in g re e n plants is the majo r so urce o f carbo hydrate s.majo r so urce o f carbo hydrate s.

CO2 + H2O CO2 + H2O carbohydrates + O2 carbohydrates + O2

Play bo th Play bo th structuralstructural and and functionalfunctional ro le in living o rg anisms.ro le in living o rg anisms.

ClassifiCation of ClassifiCation of CarbohydratesCarbohydrates

Carbo hydrate s are classifie d into thre e Carbo hydrate s are classifie d into thre e main g ro ups acco rding to the ir main g ro ups acco rding to the ir mo le cular structure , name ly:mo le cular structure , name ly:

1 . Mo no saccharide s1 . Mo no saccharide s 2 . Disaccharide s2 . Disaccharide s 3 . Po lysaccharide s3 . Po lysaccharide s

MonosaCCharidesMonosaCCharides

Simple sugars that disso lve in wate r Simple sugars that disso lve in wate r to fo rm swe e t so lutio ns.to fo rm swe e t so lutio ns.

Gene ral fo rmula : Ge ne ral fo rmula : (CH2O)n(CH2O)n Canno t be Canno t be hydrolyzedhydrolyzed into into simple r simple r

sugars.sug ars. Name s o f sugars usually e nd in Name s o f sugars usually e nd in –ose–ose..

All carbo n ato ms e xce pt o ne , have an All carbo n ato ms e xce pt o ne , have an –OH–OH g ro up . g ro up .

Sugar with aldehyde g ro up is calle d Sugar with aldehyde g ro up is calle d aldo-sugaraldo-sugar whe re as sugar with ke to whe re as sugar with ke to g ro up is a g ro up is a keto-sugarketo-sugar..

Mo no saccharide s co ntain Mo no saccharide s co ntain 3 3 to to 7 7 carbo n ato ms.carbo n ato ms.

Classificatio n acco rding to the Classificatio n acco rding to the numbe r o f carbo n ato ms in e ach numbe r o f carbo n ato ms in e ach mo le cule , ismo le cule , is ; ; triosestrioses (3C), (3C), pentosespentoses (5C), and (5C), and hexoseshexoses (6C). (6C).

IsomersIsomers

Two fo rms o f the same chemical.Two fo rms o f the same chemical. Pe nto se s and he xo se s fo rm ring structure Pento se s and he xo se s fo rm ring structure

in so lutio n.in so lutio n.

the fo rm with – OH be lo w the ring is alpha-glucose.

The fo rm with – OH be lo w the ring is beta-glucose.

All mo no saccharide s are re ducing sug ars.All mo no saccharide s are re ducing sug ars. Co mmo n mo no saccharide s are Co mmo n mo no saccharide s are glucoseglucose, ,

fructosefructose and and galactosegalactose..

OH

OH

H

H

HO

CH2OH

HH

H

OH

Osource and usessource and uses

Gluco se se rve s as the e sse ntial Gluco se se rve s as the e sse ntial e ne rg y so urce , and is co mmo nly kno wn as e ne rg y so urce , and is co mmo nly kno wn as blo o d sugar o r de xtro se .blo o d sugar o r de xtro se .

Fructo se is the swe e te st, o ccurs naturally Fructo se is the swe e te st, o ccurs naturally in ho ne y and fruits, and is adde d to many in ho ne y and fruits, and is adde d to many fo o ds in the fo rm o f high-fructo se co rn fo o ds in the fo rm o f high-fructo se co rn syrup .syrup .

Galactose rarely occurs naturally as a Galactose rarely occurs naturally as a single sugar.single sugar.

dIsaccharIdesdIsaccharIdes

Two mo no saccharide s jo in to g e the r by the Two mo no saccharide s jo in to g e the r by the pro ce ss o f pro ce ss o f condensationcondensation to make a to make a disaccharide .disaccharide .

Co mparative ly le ss so luble and le ss swe e t Co mparative ly le ss so luble and le ss swe e t in taste .in taste .

Co vale nt bo nd be twe e n two Co vale nt bo nd be twe e n two mo no saccharide s is kno wn as the mo no saccharide s is kno wn as the glycosidic bondglycosidic bond..

synthesIssynthesIs

mono = onesaccharide = sugar

di = two

2 sugars = disaccharide

1 sugar = monosaccharide

|glucose

|glucose

|maltose

1 sugar = monosaccharide

2 sugars = disaccharide

|glucose

|fructose

|sucrose

(table sugar)

How sweetit is!

1 sugar = monosaccharide

2 sugars = disaccharide

MilkSugar!

PolysaccharidesPolysaccharides

Po lyme rs who se subunits are Po lyme rs who se subunits are mo no saccharide s linke d to g e the r by mo no saccharide s linke d to g e the r by g lyco sidic bo nds.g lyco sidic bo nds.

Mo st co mple x and mo st abundant Mo st co mple x and mo st abundant carbo hydrate s in nature .carbo hydrate s in nature .

Usually branche d and taste le ss.Usually branche d and taste le ss. High mo le cular we ights.High mo le cular we ights. Sparing ly so luble in wate r.Sparing ly so luble in wate r.

poly = many

starchstarchglucose + glucose + glucose… = polysaccharide

starch(plant)

glycogen(animal)

energystorage

starch and glycogenstarch and glycogen

Main so urce o f Main so urce o f carbo hydrate fo r carbo hydrate fo r animals.animals.

Energ y sto rag e in Ene rg y sto rag e in plants.plants.

Fo und in fruits Fo und in fruits g rains, se e ds and g rains, se e ds and tube rs.tube rs.

Blue co lo r with Blue co lo r with io dine .io dine .

Energ y sto rag e in Ene rg y sto rag e in animals.animals.

Fo und abundantly in Fo und abundantly in live r and muscle s.live r and muscle s.

Inso luble in wate r.Inso luble in wate r. Red co lo r with io dine .Re d co lo r with io dine . Symbo lize d by the Symbo lize d by the

fo rmula : fo rmula : (C6 H1 0O5)n(C6 H1 0O5)n

Cellulose Cellulose Cell walls in plantsCe ll walls in plants• herbivo re s can dig e st ce llulo se we llhe rbivo re s can dig e st ce llulo se we ll• mo st mo st carnivo re s canno t dig e st ce llulo secarnivo re s canno t dig e st ce llulo se

that’ s why the y that’ s why the y e at me ate at me at to g e t the ir e ne rg y to g e t the ir e ne rg y & nutrie nts& nutrie nts

ce llulo se = ro ughag ece llulo se = ro ughag e• stays undig e ste dstays undig e ste d• ke e ps mate rial ke e ps mate rial

mo ving in yo ur mo ving in yo ur inte stine sinte stine s

ChitinChitin

A majo r co mpo ne nt o f A majo r co mpo ne nt o f e xo ske le to n o f e xo ske le to n o f arthro po ds e . g . lo bste rs arthro po ds e . g . lo bste rs and crabs.and crabs.