A balanced diet + practical

• carbohydrates: glucose is used to produce energy (ATP)/if too much is eaten stored as glycogen
• proteins: growth + repair of tissues
• Fats: store of energy + thermal insulation
• Water: essential part of many body functions and processes
• Iron (minerals): production of haemoglobin
• haemoglobin = found in red blood cells
• Vitamin c = mantains healthy tissue
• Fibre = provides bulk in the digestive system (prevents diarrhea)
• Sugar = added for taste + to increase shelf life --> type 2 diabetes , obesity + tooth decay
• Fat = increase taste --> obesity + heart disease
• Salt = taste / shelf life --> high blood pressure
• Practical:

  1. weigh 1g of food
  2. record starting temp of water
  3. ignite food with bunsen burner + hold under tube until fully burned
  4. record final temp of water ---> find difference
  5. use: equation
• Limitation of practical = method under-estimates energy content ---> heat energy can easily escape as it is not insulated + food may not completley burn
• improvement of prac = insulate apparatus with foil + use dataloggers
• fats = 2x energy of carbohydrates + proteins
• hazards of prac =

  • burning food is hot - hot grease could drip on you - control = hold with tongs
  • boiling tube is hot - could burn hand - heatproof gloves
• independent variable = change
• dependent variable = measure
• Control variable = factors to ensure accurate results