C4: biological molecules

• there are different tests to detect the presence of:

  starch, reducing sugars, proteins, fats & oils, vitamin c
• test for starch using iodine solution
• test for glucose/reducing sugar using Benedict's solution
• test for protein using Biuret solution
• test for lipids using ethanol
• test for vitamin c using DCPIP solution
• reagent colour - iodine

  brown
• reagent colour - Benedict

  blue
• reagent colour - ethanol

  colourless
• reagent colour - Biuret

  blue
• reagent colour - DCPIP

  blue
• positive result (starch)

  blue-black
• positive result (reducing sugar)

  orange/brick red
• positive result (lipids)

  white cloudy emulsion
• positive result (protein)

  purple
• positive result (vitamin c)

  blue colour disappearing
• DNA - molecule that has all instructions that a living organism needs to grow, reproduce & function
• DNA molecule is made up of two strands coiled together to form a double helix
• each strand of DNA contains chemicals called base
• base always pair up:

  A with T, C with G