CARBOHYDRATES

- Most carbohydrates - POLYMERS

- Polymers = LARGE, COMPLEX MOLECULES - LONG CHAINS OF MONOMERS

- Monomers = SMALL, BASIC MOLECULAR UNITS -
- E.g. - monosaccharides - amino acids - nucleotides

Made from MONOSACCHARIDES (MONOMER)

Contain elements - C - H - O

MONOSACCHARIDES
- GLUCOSE
- Hexose sugar
- Monosaccharide - 6 carbon atoms in each molecule
- 2 isomers - alpha and beta glucose
- ALPHA = OH LOW
- BETA = OH HIGH

- FRUCTOSE AND GALACTOSE

JOIN TWO MONOSACCHARIDES TOGETHER

- FORM CHEMICAL BOND (GLYCOSIDIC)

- RELEASE A WATER MOLECULE

FORM A DISACCHARIDE

GLUCOSE + FRUCTOSE = SUCROSE

GLUCOSE + GLUCOSE = MALTOSE

GLUCOSE + GALACTOSE = LACTOSE

BREAK POLYMERS APART

- Break chemical bond between monomers

- Release water molecule

ADD BENEDICTS REAGENT (BLUE)

HEAT SAMPLE IN WATER BATH BROUGH TO BOIL

- POSTIVE = COLOURED PRECIPITATE (BRICK RED)

- NEGATIVE = REMAIN BLUE

- DARKER INTENSITY OF COLOUR PRECIPITATE - MORE REDUCING SUGARS PRESENT

TEST FOR REDUCING NEGATIVE - COULD HAVE NON REDUCING IN

- BREAK THE POLYSACCHARIDES INTO MONOSACCHARIDES

NEW SAMPLE OF TEST SOLUTION

ADD DILUTE HCL

HEAT IN WATER BATH BROUGHT TO BOIL

NEUTRALISE WITH SODIUM HYDROGENCARBONATE

CARRY OUT BENEDICTS TEST

- IF NO COLOUR CHANGE - NO REDUCING OR NON REDUCING SUGARS PRESENT

MAIN ENEGERY STORAGE MATERIAL - PLANTS

- CELLS - ENERGY FROM GLUCOSE
- PLANTS - STORE EXCESS GLUCOSE AS STARCH - PLANT - NEED MORE ENERGY - BREAK DOWN STARCH

STARCH - MIXTURE OF 2 POLYSACCHARDIES OF ALPHA GLUCOSE

AMYLOSE
- LONG, UNBRANCHED CHAIN
- ANGLES OF GLY. BONDS - GIVE COIL STRUCTURE
- MAKE COMPACT - GOOD STORAGE - FIT MORE INTO SMALL SPACE

AMYLOPECTIN
- LONG, BRANCHED CHAIN
- SIDE BRANCHES - ALLOW ENXYMES TO BREAK DOWN GLY. BONDS EASILY
- GLUCOSE RELEASE QUICK

STARCH - INSOLUBLE - NO EFFECT ON W.P
- NO MOVEMENT OF WATER IN VIA OSMOSIS
- GOOD FOR STORAGE

ADD IODINE DISSOLVED IN POTASSIUM IODIDE SOLUTION

POSITIVE = BROWNY ORANGE --> BLUE-BLACK

MAIN ENERGY STORAGE MATERIAL - ANIMALS

- ANIMALS STORE EXCESS GLUCOSE - AS GLYCOGEN

SIMILAR STRUCTURE TO AMYLOPECTIN
- MORE SIDEBRANCHES
- GLUCOSE RELEASED QUICKER
- IMPORTANT FOR ENERGY RELEASE

COMPACT
- GOOD FOR STORAGE

MAJOR COMPONENT - PLANT CELL WALLS

- LONG, UNBRANCHED CHAIN - BETA GLUCOSE

BETA GLUCOSE BOND - FORM STRAIGHT CELLULOSE CHAINS
- LINK BY HYDROGEN BONDS
- FORM STRONG FIBRES - MYOFIBRILS

- PROVIDE STRUCTURAL SUPPORT FOR PLANTS