Science at key stage 3    (Year 8)

• identify some reasons why food is important, eg as raw material, for growth, for energy

• identify foods which are rich in particular nutrients
• use chemical tests to identify proteins, carbohydrates and fats
• work safely with chemicals
• construct a Venn diagram showing the combinations of nutrients in each food sample tested

• use ICT to produce graphs or displays relevant to the question asked
• use data to show that vitamins and minerals are present in foods in smaller amounts than the other nutrients
• describe, eg in an information leaflet, good sources of one nutrient and the importance of that nutrient in the diet
• identify the main role of proteins, carbohydrates and fats in the diet

• explain that a healthy diet contains a balance of six groups of chemicals (proteins, carbohydrates, fats, vitamins, minerals, fibre) and water

• critically assess the sources of secondary data, and use selected sources for a purpose
• identify factual information and distinguish it from an opinion/claim, focusing on the language used
• recognise when presenting results that knowledge is incomplete and interpretation of evidence is difficult

• select relevant information
• indicate where knowledge is not sufficient to draw a firm conclusion
• represent information in a format appropriate to the audience

• generate appropriate questions together with answers related to the content of the unit

• describe how food passes along a digestive tube which runs through the body
• offer suggestions about what happens to food as it passes through this tube
• make links between the model gut and the digestive system
• use scientific knowledge to explain observations

• state that small molecules can pass through the wall of the small intestine
• explain that starch, protein and fat molecules are too large to be absorbed
• explain that specific vitamins and minerals are generally smaller and can be absorbed by the body
• produce a sequence of diagrams to illustrate that larger molecules are broken down to form smaller molecules in the gut

• state that food is digested by enzymes in the gut to form smaller molecules and that these pass into the blood
• describe the processes involved, eg by drawing diagrams, by using models, in writing

• suggest relevant variables, eg pH, temperature
• identify a way to keep variables, eg temperature, constant
• identify the conditions under which digestion occurs, eg at a temperature of 37?C, and relate these to their results

• state that the blood transports products of digestion to every cell in the body
• use models to describe how smaller molecules are transported in the blood
• state that some food material cannot be digested and is passed out of the body as faeces

• identify appropriate connections between ideas in this unit and explain their reasoning