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Home , Amylopectin, Amylose, Carbohydrate, Glycogen, Maltose, Sucrose

Summary of Structures

See original handout pages for the following:

1. Open chain and cyclic forms of 2. structures: , , 3. Shorthand structures of , (), and 4. Cyclization of and and rules for writing Hayworth projection formulas (“LURD”, “BUAD”)

This version of the presentation does not have some graphics in the interest of making the file smaller

Chair Conformation of

Fig 9-8

1 Reducing : Aldoses

HO 6 Fig 9-10 5 O 4 OH 1 2 OH HO 3 OH α-D-glucopyranose 2 Cu+2

OH-

Cu2O(s) OH- HO 6

5 O 4 OH 1 O 2 Alkaline reagent with copper(II) chelator: HO 3 OH Tartarate: Fehlings’s α-D-glucuronic lactone Citrate: Benedict’s solution

Reducing Sugars: Open Chain Ketoses!

O O

1 CH2OH 1 CH 1 CH

2 C O H C OH C H 2 HO 2 +2 HOC H 2 Cu Cu2O(s) 3 - HOC H HOC H OH 3 + 3 H C OH 4 H C OH 4 H C OH H C OH 4 5 H OH 5C H 5C OH CH OH 6 2 CH OH 6 2 6CH2OH OPEN CHAIN FORM rearrances to mixture of aldoses which can be oxidized by Cu2+ reagents either as the open chain form or as the cyclic form

2 Functions of Monosaccharides

Glyceraldehyde and (C3): -Intermediates in -Precursors for used for and phosphoglyceride

Ribose (C5): (CH2O)n partly oxidized, readily available source -Source of energy for and

- unit for -derived coenzymes (NAD+, FAD, etc) -Monomer unit for RNA

Ribofuranose in RNA and coenzymes

NICOTINAMIDE ADENINE DINUCLEOTIDE

( B3 niacin(amide))

H O

C NH2 O - N O P O O

OH OH O NH2 N N

N N - O PO O O

OH OH **NAD (oxidized form)

3 Functions of Monosaccharides (CH2O)n partly oxidized, readily available energy source

Glucose (C6): -Source of energy for plants and animals in glycolysis -Monomer unit for cellulose in plants

Fructose (C6): -Source of energy for plants and animals in glycolysis

DISACCHARIDES: Maltose Provides energy for maltose HO HO germinating seeds O O HO HO (breakdown product of HO O OH amylopectin and amylose OH OH O-α-D-glucopyranosyl-(1 -> 4)-α (or β)-D-glucopyranose in germinating seeds) (ending = "ose" since anomeric OH is free)

Hydrolyzed into by an called α-glucosidase

4 : Sucrose

sucrose Storage saccharide in… HO O HO glucose = α HO … beets OH O O HO = β …sugar cane HO OH

OH O-α-D-glucopyranosyl-(1 -> 2)-β-D-fructofuranoside (ending = "oside" since anomeric O is derivatized) Hydrolyzed into glucose and fructose by an enzyme called

DISACCHARIDES: Lactose

lactose HO O OH HO HO O O HO OH HO

OH

O-β-D-galactopyranosyl-(1 -> 4)-β -D-glucopyranose

Found in , lactose provides energy to nursing infant Hydrolyzed by laccase = β-galactosidase

5 WRITING AMYLOSE

HO HO O O HO HO HOO O OHO OH OH

Linear α-(1 ->4) linked polymer of glucose

The reducing end of the polymer The nonreducing end () of the polymer Fig 09-16.GIF

THREE-DIMENSIONAL AMYLOSE

~ 20 D

~ 20 D

Fig 09-16.GIF

http://www.wellesley.edu/Chemistry/chem227/sugars/amylose-end.gif

6 BIOLOGICAL OF AMYLOSE Amylose is a storage polymer for glucose in plants

Q: How is the structure of amylose related to its biological function?

A: The amylose polymer is a storage polymer for glucose. It has a helical structure which allows for more glucose to be packed into a given volume.

HYDROLYSIS OF AMYLOSE: α- (in saliva and pancreatic of animals) (in plants and all other living ) α-Amylase is an endoglycosylase: It randomly hydrolyzes within the linear polymer (> 3) giving a mixture of maltose and glucose

HO HO O O HO HO

O O O OH OH

Linear α-(1 ->4) linked polymer of glucose

7 OF AMYLOSE: β-Amylase (in germinating seeds, sweet potatoes)

β-Amylase is an exoglycosylase: It removes maltose units from the nonreducing ends of the amylose (> 4)

HO HO O O HO HO

HOO O O OH OH

Linear α-(1 ->4) linked polymer of glucose

The nonreducing end of the polymer

How are Glycogen and Amylopectin Different? Polymer Occurance Function Glycogen , muscle Storage polymer 4-10 glucose/linear segments for glucose

Amylopectin Plants " " > 12 glucose/linear segments

How are the structures of glycogen and amylopectin related to their biological function?

8 oxidation (lab) and can determine degree of brancing

METHYLATION OF GLYCOGEN VERSUS AMYLOPECTIN HO O OH branch point O O α (1 - 6) OH HO HO HO O O O O OH OH OH OH HO O O O O O OH OH OH α (1 - 4) OH OH nonreducing end reducing end linkages O

CH3ICHOR 3OSOCH3 O H+

Polymer I: 8.5 % 2,3 dimethyl glucose Polymer II: 2.1 % 2, 3 dimethyl glucose + what other products? (draw structural formulas for all products) Which polymer is glycogen and which is amylopectin and why?

Enzyme that hydrolyze glycogen Polymer Hydrolytic Glycogen Glycogen  gluc-(gluc)n + Pi (gluc)n + gluc-1-Pi

HO O OH branch point O O α (1 - 6) OH HO HO HO O O O O OH OH OH OH HO O O O O O OH OH OH α (1 - 4) OH OH nonreducing end O reducing end linkages O -O P OH -O

9 Enzyme that hydrolyze amylopectin Polymer Hydrolytic Enzymes Amylopectin Phosphorylase  gluc-(gluc)n + Pi (gluc)n + gluc-1-Pi

HO O OH branch point O O α (1 - 6) OH HO HO HO O O O O OH OH OH OH HO O O O O O OH OH OH α (1 - 4) OH OH nonreducing end O reducing end linkages O -O P OH -O

What happens next with these branched polymer?

Fig 15-13.GIF

10 WRITING CELLULOSE STRUCTURE

HO O O HO HO O O OH HO Actual O orientation OH of adjacent Linear β-(1 ->4) linked polymer of glucose glucose residues:

Fig 9-17.GIF

Linear fibers aggregate into sheets…

Sheets aggregate into microfibrils…

Microfibrils aggregate into stiff, rigid structures

11 What is the biological function of cellulose?

Cellulose provides… 1. Structural ridigity to plants 2. Another polymer for glucose storage

How is the structures of cellulose related to its biological function?

What enzyme can hydrolyze cellulose?

HO O O HO HO O O OH HO HO O O HO OH HO O O OH HO O OH

12