SACCHARIDES PROPERTIES

Introduction:
Saccharides are organic molecules consisting of C, H and O atoms. The empirical formula usually is Cn H2n On. Are divided in two groups:
    -Monosaccharides: formed by linear a carbon chain, are the building blocks of oligo and polysaccharides. They have a one functional group: cetone (C=O) or aldehyde (COH). 
    -Oligosaccharides: small polymer containing between 2 and 10 monosaccharides.
    -Polysaccharides: big polymers with more than 10 monosaccharides.

Materials:

-Test tube rack

-10mL Pipet

- 5 spatula

-5 test tubes

-1 dropper

-Distilled water

-Lactose
-Maltose
-Glucose
-Sucrose
-Starch
-Lugol's  iodine

Objectives: 

1- Identify different sugars from its properties.

2- Differentiate monosaccharides and disaccharides.

3- Understand the relation between structure and some proporties.

Procedure:

We started off by testing some physical properties of the saccharides we have in the lab, such as flavour, the structure and color.

To test the flavour we tasted a small part of each saccharide, and we asked ourselves wether it was sweet or sour?

And by obvserving a small amount of each saccharide under magnification we tested the crystal.

Lastly we tested the color of each element, was it creamy, white or transparent?

	GLUCOSE	MALTOSE	SUCROSE		LACTOSE	STARCH
Flavour	sweet	sweet	sweet		no sweet	no sweet
Clystalline	crystaline	no crystaline	crystaline		powder	crystaline
Colour	white	cream	white		white	white
Solubility	soluble	insoluble	soluble		soluble	insoluble
Lugol’s iodine	negative	negative		negative	negative	positive

TO TEST SOLUBILITY:

- Clean and dry 5 test tubes and label them: G, M, L, SU, S

-Pour 5mL of water in each test tube.

-With the help of a spatula, put a small amount of each saccharide inside the labelled test tube and test if they are soluble or insoluble.

- Observe is each saccharide forms a mixture called dissolution or a colloidal suspension.

- Finally, add 2 drops of Lugol's iodine to each test tube and test if the reaction is positive or negative. Lugol's is a solution of elemental iodine (I) and potassium iodine (KI) in water that is ise to test a saccharide. The reaction is positive if iodine reacts by turning from yellow to a purple, dark-blueish colour.