Biology 1.3 Nutrients and food test

Biology 1.3 Nutrients and food test

1. Food Tests

   • iodine: Tests for starch Yellow-brown > blue black
     • 3. Check to see if there's a negaive or positive colour change
   • Ethanol: Tests for fat Colourless> white emulsion
     • 2. Add a few drops of the solution to the test tube
   • Biuret: Tests for protein Blue> Purple
     • 1. Add 1cm3 of the substance to a test tube, using a syringe
   • Benadict's: Tests for glucose Blue> Brick Red
     • If testing using benadict's, put the test tube in a water bath for a few minutes after step 2.

2. Biological molecules

   • Protein
     • Used for growth, repair, collegine, enzymes and hormones
     • Made up of amino acids
   • Fats/ Lipids
     • Made up of 3 fatty acids and glycerol
     • Used for insulation of heat, protection of organs and store of enery
   • Carbohydrates
     • Simple Carbohydrates
       • Glucose, Sugar and Lactose are a source of energy
     • Complex Carbohydrates
       • Cellulose is used as a cell wall in plants
       • Starch is used as an energy store in plants
       • Glycogen is used as an energy store in animals