Macromolecules are polymers made through dehydration synthesis (reaction that removes a molecule of water).

Examples of macromolecules are:Carbohydrates – sugarsProteins- amino acidsLipids- fatty acids and glycerolNucleic acids – nucleotides

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Composed of monosaccharaides, disaccharides and polysaccharides.

Monosaccharaides: simple sugars that contain a ratio of C:H:O of 1:2:1Examples glucose, fructose and galactose

Disaccharides: composed of 2 monosaccharaidesExamples sucrose, maltose and lactose

Polysaccharides: chain of 3 or more monosaccharaides. Starch, glycogen and cellulose

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Sugars with free carbonyl groups are called reducing sugars. They cause the copper (Cu ²⁺) in the Benedict’s reagent to

become reduced (gain electrons) to form Cu ¹⁺, forming Cu₂O . The reaction occurs when the mixture is heated to 100 °C.

water glucose sucrose starch milk apple juice potato

Before the addition of Benedict’s reagent

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After the addition of the Benedict’s reagent

After the application of heat for 3 minutes.

RESULTS:Blue= negativeRed = high concentrationOrange and yellow = medium

concentrationGreen = low concentration

Water glucose sucrose starch milk apple potato juice juice

- + - - + + + 5

Starch is a polysaccharide consisting of many glucose monomers linked together into long branching chains. It is the primary storage carbohydrate in plants. In the presence of iodine (I₂-KI) a solution containing starch will turn blue-black in color.

The test tube rack contains substances to be tested.

water glucose sucrose starch milk apple potato juice juice

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Blue-black = positiveYellow = negative

water glucose sucrose starch milk apple potato juice juice

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Some water, 10 drops of oil, 5 drops of Sudan IV were added to a tube.

Detergent water was added to the test tube and mixed. Detergent is an emulsifier. It surrounds the oil droplets and allows them to stay suspended in the water. The suspended oil droplets stained with Sudan IV give color to the solution. This is an emulsion.

After the test tube sits, the oil will separate from the water.

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In the presence of proteins, biuret reagent reacts with the peptide bonds between the amino acids changing in color from light blue to violet. The intensity of the violet color is proportional to the protein concentration. Biuret reagent does not react with free amino acids.

Solutions tested for proteins

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Light blue= negativeViolet = positive

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