CARBOHYDRATES

Photosynthesis

Carbon Dioxide + Water Carbohydrate + Oxygen

(Glucose)

Sunlight

CO2

H2O

O2

Carbohydrate

Respiration

Carbohydrate + Oxygen Carbon Dioxide + Water (Glucose)

Oxygen

Carbohydrate

Carbon Dioxide

Water

ENERGY!!

Definitions of processes

Photosynthesis: Plants making carbohydratesCarbon dioxide + water Carbohydrate + Oxygen

Respiration: Animals use carbohydrates (and oxygen)

to get energyCarbohydrate + Oxygen Carbon dioxide + water

(plus ENERGY)

Carbohydrate Molecular Formula

glucosefructosemaltosesucrosestarchcellulose

C6H12O6

C6H12O6

C12H22O11

C12H22O11

polymerpolymer

Grouping Carbohydrates

Condensation Polymerisation

G OH HO

Glucose Monomer

G OH HO G OH HO HH

Starch Polymer

Water Molecule

Summary

Testing for carbohydratesBenedict’s Iodine

Glucose

Fructose

Maltose

Sucrose No reactionNo reaction

No reaction

No reaction

No reaction

No reaction

Blue > Red

Blue > Red

Blue > Red

Starch Orange > Black

Hydrolysis:Breaking down of large molecules into small molecules by adding in molecules of waterFor carbohydrates:

STARCH + WATER GLUCOSE

Condensation Polymerisation: Joining together of small monomers to make a polymer by eliminating waterFor carbohydrates:

GLUCOSE STARCH + WATER

Definitions of processes

UNIT 2: PPA 3Hydrolysis of STARCH

1. Set up a water bath and begin to heat water

2. Using a measuring cylinder, add 20ml starch solution to each

of two boiling tubes

3. To one boiling tube add 2ml of water using a syringe

(this will be your CONTROL)

To the other, add 2ml of hydrochloric acid

4. Place the boiling tubes in the water bath and gently boil for

approx 10 mins

Now continue from STEP 4 of PPA sheets

UNIT 2: PPA 3Hydrolysis of STARCH

Aim: To hydrolyse starch using hydrochloric acid as a catalyst

Procedure: (1) Water was added to one of the boiling tubes as a control,

this let us see the effect of the acid

(2) The Benedict’s solution turned from blue to red which

indicated the starch had been hydrolised to glucose

Conclusion: The starch was broken down by the acid into glucose

Enzyme Activity

Facts about Enzymes:

• Enzymes are BIOLOGICAL CATALYSTS.

•These are present in living organisms to catalyse

reactions which are necessary for life.

• Enzymes will only catalyse one specific reaction.