Biological molecules and food tests

Learning objectives

List the chemical elements that make up carbohydrates and fats (carbon, hydrogen and oxygen) and proteins (carbon, hydrogen, oxygen, nitrogen and often sulfur)

Describe how large molecules are built from smaller ones: starch, glycogen and cellulose from glucose, proteins from amino acids, and fats and oils from fatty acids and glycerol

Describe the food tests for starch (iodine solution), reducing sugars (Benedict's solution), protein (biuret test), fats and oils (ethanol emulsion test) and vitamin C (DCPIP), and state the positive result of each

Describe the structure of DNA as two strands coiled into a double helix, held together by pairs of bases with A paired to T and C paired to G (Extended)