2(e) Nutrition
16 specification points in sub-topic 2(e).
Specification points
2.18: Photosynthesis and energy conversion
Photosynthesis: plants transfer light energy into chemical energy stored in glucose.
2.19: Photosynthesis equations
The word and balanced symbol equations for photosynthesis.
2.20: Factors affecting the rate of photosynthesis
How light, carbon dioxide and temperature act as limiting factors on photosynthesis.
2.21: Leaf structure and photosynthesis
How the tissues of a leaf are arranged for light capture, gas exchange and transport.
2.22: Mineral ions for plant growth
Why plants need nitrate and magnesium ions, and what happens when they are short of them.
2.23: Photosynthesis investigations
Practicals showing that photosynthesis needs light, carbon dioxide and chlorophyll, and gives out oxygen.
2.24: A balanced diet
What a balanced diet is, and why people need different proportions of nutrients.
2.25: Sources and functions of dietary components
Food sources and uses of each nutrient group, including vitamins, minerals, water and fibre.
2.26: Energy requirements
Why energy needs change with activity level, age and pregnancy.
2.27: The human alimentary canal
The route food takes through the alimentary canal and what each organ does.
2.28: Peristalsis
Peristalsis: how muscles in the gut wall squeeze food along.
2.29: Digestive enzymes
How amylase, maltase, proteases and lipases break large food molecules into small ones.
2.30: Bile production and storage
Bile is made in the liver, stored in the gall bladder and released into the duodenum.
2.31: Roles of bile
The two jobs of bile: neutralising stomach acid and emulsifying fat for lipase.
2.32: Absorption in the small intestine
How villi give the small intestine a huge surface for absorbing digested food.
2.33B: Energy content of a food sample
Practical: burning food under water to estimate the energy it contains.