Food groups and tests

• Where are carbohydrates mostly found?

  Starchy foods, such as rice, potatoes and pasta
• Why do we need carbohydrate?

  The provide us most of the energy we need to carry out chemical reactions and to move around
• Where are lipids mostly found?

  Cheese, oil, chocolate
• Why do we need lipids?

  Provide a longer term store of energy,keep us warm by insulating us and protect our organs
• Where are proteins mostly found?

  Nuts, meats and beans
• What do we need proteins for?


  Growth, repair damaged tissue and energy(only if we don’t have enough carbohydrate)
• What are Vitamins?

  They are organic molecule, meaning they’re made by living organisms
• what are minerals?

  Inorganic molecules
• Where can we gain vitamin A?

  Liver or leafy vegetables
• Why do we need vitamin A?

  Good vision, healthy hair and skin
• Where is vitamin c found?

  Fruits and vegetable e.g. oranges
• Why do you need vitamin c?

  To prevent getting the disease scurvy
• Where can we get vitamin d?

  Sunlight and eggs
• Why do we need vitamin d?

  Calcium absorption
• Where is calcium(mineral) found?

  Dairy products and leafy vegetables
• Why do you need calcium?

  Bone health, if you don’t eat enough it can cause rickets(bones being deformed)
• Where is ion(mineral) found?

  Read meat, spinach and beans
• Why do you need ion?

  Important component of haemoglobin which helps reduce blood cells transport oxygen
• What happens if you don’t have enough ion?

  You can get anemia, where you can’t transport as much oxygen to your tissue.
• What is fibre?

  A type of carbohydrate which helps food move through our instestine properly.
• Why do we need fibre?

  Help us not get diarrhoea
• Food tests


  1. Prepare food sample

  2. Crush food with mortar and pestle

  3. Dissolve in distilled water

  4. Filter solution
• Sugars


  Small units that all carbohydrates are made of
• Types of sugars


  • Reducing sugars
  • Non-reducing sugars
• Benedict's test for reducing sugars

  1. Prepare food sample

  2. Transfer 5cm3 to test tube

  3. Heat in 75C water bath

  4. Add Benedict's solution

  5. Observe colour change
• Starch


  A type of carbohydrate that is a larger and more complex molecule than sugars
• Iodine test for starch

  1. Take 5cm3 of food sample

  2. Add iodine solution

  3. Observe colour change to browny orange color. 4. Gently shake it and if starch is present, the colour will turn from that browny orange colour to blue/black colour
• Biuret test for proteins

  1. Take 2cm3 of food sample

  2. Add 2cm3 Biuret solution

  3. Observe colour change from blue to purple if it contained protein
• Sudan 3 test for lipids

  1. Take 5cm3 of food sample(not filtered)

  2. Add 3 drops Sudan 3 stain

  3. Observe red layer at the top if lipids was present
• In the Benedict test if no sugars are present what colour will it turn?

  It will stay blue.
• In the Benedict test if there a reducing sugars present, what colour will it turn?

  Brick red
• Which mineral is important for strong bones?

  Calcium
• Which disease can be caused by lack of vitamin C?


  scurvy
• Explain why it is important that we get enough iron in our diet. 

  Iron is an important component of haemoglobin and Haemoglobin is the protein in red blood cells that allows them to transport oxygen around the body.
• What are the 3 main ways by which we lose water from the body?

  Breathing,sweating and urinating
• Which vitamin or mineral ion helps us to absorb calcium, and can be made by the body, using sunlight?

  Vitamin D
• Balanced diet


  A balanced diet is a diet that includes appropriate proportions of all the different biological molecules, including carbohydrates, proteins, lipids, vitamins, minerals, dietary fibre, and water. 
• How much energy we need depend on 3 factors:

  1. Activity level - The more active you are, e.g. if you're an athlete, the more energy you need
  2. Age - Teenagers often need a lot of energy because they're growing, whereas elderly people need less. 
  3. Pregnancy - Pregnant women need more energy because the baby growing inside them requires a lot of energy.