food tests

• What is the main function of the digestive system?

  Digests and absorbs nutrients
• What is the main function of the respiratory system?

  Absorbs oxygen from the air
• What is the main function of the circulatory system?

  Moves essential substances around the body
• Why is damage to any of the organ systems serious?

  Because it can be fatal
• What is the process by which water molecules move from areas of high water concentration to lower water concentration?

  Osmosis
• What is the process by which substances move from high concentration to low concentration?

  Diffusion
• What is the process by which substances move from low concentration to high concentration using energy from respiration?

  Active transport
• Why do areas where movement of substances takes place have highly folded membranes?

  To give a large surface area
• Why do areas where movement of substances takes place have thin walls?

  To give a short diffusion path
• Why do areas where movement of substances takes place have a good blood supply?

  To remove substances and maintain concentration gradients
• What is the chemical used to test for starch?

  Iodine
• What is the colour change when starch is present?

  From orange to blue-black
• What is the chemical used to test for sugar?

  Benedict's solution
• What is the colour change when sugar is present?

  From blue to orange-red
• What is the chemical used to test for protein?

  Biuret solution
• What is the colour change when protein is present?

  From blue to lilac/purple
• What is the chemical used to test for fat?

  Ethanol and water
• What is the colour change when fat is present?

  From clear to cloudy white
• What are the main components of a healthy diet?

  • Carbohydrates
  • Protein
  • Fats
  • Water
  • Vitamins
  • Minerals
  • Fibre
• What are the functions of the different nutrients in the body?

  • Carbohydrates: Energy
  • Protein: Growth and repair
  • Fats: Energy
  • Water: Major component of bodily fluids
  • Vitamins: Good health
  • Minerals: Good health
  • Fibre: Healthy colon
• How do you test for starch, sugar, protein, and fat?

  • Starch: Iodine solution, colour change from orange to blue-black
  • Sugar: Benedict's solution, colour change from blue to orange-red
  • Protein: Biuret solution, colour change from blue to lilac/purple
  • Fat: Ethanol and water, colour change from clear to cloudy white
• Why is it important to improve diet and lifestyle to reduce the risk of heart disease and other health problems?

  To reduce the risk of serious and fatal health problems
• What is the role of the circulatory system in maintaining concentration gradients?

  To remove substances and maintain concentration gradients
• What is the function of mitochondria in active transport?

  To provide energy from respiration
• What is the difference between diffusion, osmosis, and active transport?

  Diffusion: movement from high to low concentration, Osmosis: movement of water molecules from high to low concentration, Active transport: movement from low to high concentration using energy from respiration
• What safety precautions should be taken when testing for starch, sugar, protein, and fat?

  Wear goggles, avoid open flames, and allow hot equipment to cool