Page 139 - Knowledge Organiser Yr7 24-25

Knowledge Base: Science 7.12 Nutrition Year 7
2. Energy Requirements
2.1
What information can be found on nutrition labels?
The amount of energy the food contains and the proportion of nutrients in the food
2.2
What is the unit for energy given on nutrition labels?
Joules (J) or Kilojoules (kJ)
2.3
Different people have different energy requirements. What affects energy requirements?
Age, sex, body size, level of activity
2.4
How do energy requirements change with increasing exercise levels?
The more exercise you do, the more energy your body requires
2.5
Which type of fat is more unhealthy, saturated or unsaturated?
Saturated
2.6
What is the difference between saturated and unsaturated fats?
• Unsaturated fats are normally liquid at room temperature and derived from plants
• Saturated fats are normally solid at room temperature and derived from animals
3. Food Tests
3.1
How can you prepare a sample of food for a food test?
Crush the food (using a pestle and mortar), add a few drops of water and mix well
3.2
What is the name of the chemical used when testing for starch in a food sample?
Iodine
3.3
What colour is iodine and what colour does it turn in the presence of starch?
Brown, turns black/dark blue if starch is present
3.4
What is the name of the chemical used when testing for lipids (fats) in a food sample?
Ethanol
3.5
What colour is ethanol and what happens to ethanol in the presence lipids (fats)?
Colourless, solution turns cloudy if lipids (fats) are present
3.6
What is the name of the chemical used when testing for sugar (glucose) in a food sample?
Benedict's solution
3.7
What colour is Benedict’s solution and what colour does it turn in the presence of sugar (glucose)?
Blue, turns orange/red if sugar (glucose) is present
3.8
What is the name of the chemical used when testing protein in a food sample?
Biuret solution
3.9
What colour do the Biuret solutions turn if protein is present in the food sample?
Purple
Figure 2: Examples of Nutrition Labels
139