1. Photosynthesis Make sure you revise: What Photosynthesis is
Equation for Photosynthesis
Factors that effect the rate of Photosynthesis
Use of glucose from Photosynthesis
Healthy plant growth (nitrates ions)

2. Carbon dioxide + water (+ light energy)
Photosynthesis
Photosynthesis can be summarised by the equation:
Carbon dioxide + water (+ light energy) 
Glucose + Oxygen
Photosynthesis is when green plants use light energy to make their own food During photosynthesis: light energy is absorbed by chlorophyll (a green substance found in chloroplasts of some plant cells light energy converts carbon dioxide and water into sugar (glucose) oxygen is released as a by-product.

3. What factors affect the rate of Photosynthesis

4. Limiting carbon dioxide levels
Increasing carbon dioxide levels increases the rate of photosynthesis up to a point.
Eventually one of the other factors (temperature and light) becomes limiting
If there is too little carbon dioxide the rate will slow down.
Carbon dioxide maybe limited in an enclosed space eg, a greenhouse on a sunny day or in a rapidly photosynthesising rain forest

5. Limiting light intensity
Increasing light intensity increases the rate of photosynthesis up to a point
When a certain light intensity is reached the rate of photosynthesis stays constant
Eventually one of the other factors becomes limiting

6. Limiting temperature
If it is cold then enzymes do not work effectively slowing down the rate.
The rate of photosynthesis increases steadily with a rise in temperature up to a certain point (35-40ºC = optimum temp)
After this the enzymes are destroyed and the reaction stops completely.

8. Healthy plant growth Plant roots absorb mineral ions
needed for healthy growth
For healthy growth plants need
mineral ions including
Nitrates and
Magnesium
Mineral ions:
Nitrates
Magnesium
Needed for:
Nitrates produce amino acids which are then used to make proteins for growth
Needed for chlorophyll production
Symptoms shown by plants growing in conditions where mineral ions are deficient:
Stunted growth
Yellow leaves

9. Photosynthesis quiz