Carbohydrates (CHO) – Simple Sugars

Disaccharide-Two monomers (glycosidic bond)-Condensation / dehydration rxn- anomeric OH group of 1 monomer & any other –OH on the other sugar.

Glycosidic bond

Condensatn rxn

- specific pattern

Maltose = Glucose--1,4-Glucose Lactose = Galactose--1,4-Glucose Sucrose = Glucose--1,2-Fructose

http://www.youtube.com/watch?v=XOAd8tfD6Sg

Anomeric Carbon & OH

or

Aldohexose Eg: glucose Ketohexose Eg: fructose

Monosaccharide - ose - single sugar units (CH2O)n - # of C (tri-, pent-, hex-)- aldose / ketone (C=O)- spatial arrangem (chiral C)

Uses- energy sources, building blocks, raw material

Easily oxidized

Common Disaccharides

Glycosidic Bond Formation

1) Count the C

2) Identify or

3) Name the bond

specific pattern• primary structural difference• Linear polymers = all residues are involved in two glycosidic linkages except at each end of the chain • Branched polymers can be formed that consist of residues with 3 glycosidic bonds.

Reducing sugar = free anomeric carbon (all mono-S & some di-S).

Benedict’s test and Fehling’s test.

POLYSACCHARIDES macromo polymers (100 – 1000s mono-S).Branched / linear

- large & insoluble - compact shapes, - hydrolysed easily to form sugars

Animals - Glycogen glycogen granules-liver & skeletal muscle - glucose - extensively branched. - Every 8-12 glucose units. - > compact than amylopectin.- red-violet colour with iodine-potassium iodide solution.

Storage Support

Plants - Starch granules in plastids- carbon & energy sources glucose-Amylose & Amylopectin

Plants - cellulose- cellulose glucose- Diff 3D shapes, f(x)- Alternate inverted mol- long, unbranched str chain.- // chains -OH project outwards - H-bonds ./. neighbourg chains.- cross-linking - form microfibrils, & macrofibrils.

- High tensile strength - Stability -withstand forces fr all directions- Fibrils - different orientations in different layers- fully permeable - food source

Storage Poly-S

- major source of energy for cells: - cellular respiration, = ATP, CO2 & H2O production

- large size makes it relatively insoluble in water (no osmotic or chemical influence in the cell)

- fold into compact shapes, (store many glucose molecules) within a small volume in the cell.

- easily converted to sugars by hydrolysis when required, thus releasing energy required.

Amylose• linear (100 – 1000s -glu w -(1,4) glycosidic bonds) • compact - helically coil w 6 glu / turn• form micelles w helical poly-S chain• blue-black colour with I2 –KI)

Amylopectin• > complex (-glucose residues, but with 2 different linkages)• twice as many -glucose residues as amylose• (1-4) glycosidic bonds giving it the linear structure. • (1-6) glycosidic bonds = branched. (12-30 residues)• Branching - simultaneous breakdown by enzymes - highly compact•red-violet colour with I2-KI

Starch phosphorylase Amylose - -amylase and -amylase

Amylopectin - - & -amylase & (16)-glucosidase Animals - Salivary & pancreatic -amylase. (16)-glucosidase

Debranching enzymes, amylo--(16)-glucosidase,

Glycogen phosphorylase

(14) bonds - resistant to acid / amylases cellulases (-glucosidases)

Relating Structure of Starch to its Storage Function

Structure Significance

Large molecule Insoluble; thus it is ideal storage material since it does not affect the osmotic potential within cells and living organisms.

Anomeric carbon involved in glycosidic bond formation leaving few free groups

This makes starch an unreactive and stable compound, again, ideal as storage substance.

Composed of several hundreds to thousands of glucose monomers

The large number of glucose molecules act as a large store of carbon (building block) and energy (respiratory substrate).

Glucose units linked by (14) glycosidic bonds

Starch may be easily hydrolysed by enzymes present in plants and most organisms.(14) glycosidic bonds result in helical coil so that structure is more compact and ideal for storage.

Amylose molecules are helical in shape

The resulting compact shape is ideal for storage.

Amylopectin molecules are highly branched

The compact shape allows for easy storage.Many enzymes can hydrolyse it easily at the same time for use by organisms.

Relating Structure of Glycogen to its Storage Function

Structure Significance

Large molecule Insoluble; thus it is ideal storage material since it does not affect the osmotic potential within cells and living organisms.

Anomeric carbon involved in glycosidic bond formation leaving few free groups

This makes glycogen an unreactive and stable compound, again, ideal as storage substance.

Composed of several hundreds to thousands of glucose monomers

The large number of glucose molecules act as a large store of carbon (building block) and energy (respiratory substrate).

Glucose units linked by (14) glycosidic bonds

(14) glycosidic bonds can be hydrolysed by glycogen phosphorylase to release glucose-1-phosphate.(14) glycosidic bonds result in helical coil so that structure is more compact and ideal for storage.

Glycogen is highly branched

The compact shape allows for easy storage.Many enzymes can hydrolyse it easily at the same time for use by organisms.

Relating Structure of Cellulose to its Structural Function

Structure Significance

Large molecule Insoluble; thus it is ideal storage material since it does not affect the osmotic potential within cells and living organisms.

Composed of several hundreds to thousands of glucose monomers

The large number of glucose molecules act as a large store of carbon and energy for organisms that can feed on it.

Glucose units linked by (14) glycosidic bonds

(14) glycosidic bonds result in long, straight chains.

Long and unbranched Acts as scaffold important for supportive function.

- OH groups project from cellulose chains Allows H-bonds to form between chains forms extensive cross-linkages in microfibrils results in high tensile strength important for structural strength

Chains associated in groups to form microfibrils and macrofibrils

This results in high tensile strength that translates further into mechanical strength.

FYI : L or D sugars

For sugars with more than one chiral center, the D or L designation refers to the asymmetric carbon farthest from the aldehyde or keto group.

Most naturally occurring sugars are D isomers.

D & L sugars are mirror images of one another. They have the same name. For example, D-glucose and L-glucose are shown at right.