B2.3 Photosynthesis

HideShow resource information

B2.3.1 Photosynthesis Equation

Raw materials in reaction:

  • Carbon dioxide
  • Water

Conditions needed:

  • Light energy 
    • Trapped by molecules of...
  • Chlorophyll
  • Enzymes


  • Glucose
  • Oxygen
    • Released as a by-product
1 of 4

B2.3.1 Leaf Diagram


2 of 4

B2.3.1 Uses of Glucose

Glucose is used in plants and algae in the following ways:

  • Broken down to release energy in respiration
  • Converted to cellulose to strengthen cell wall
  • Converted to fat or oil for storage
  • Converted to insoluble starch for storage
    • To test for photosynthesis, do a starch test using iodine solution on leaf
  • Converted to proteins
    • Nitrate must be absorbed from mineral ions in soil
3 of 4

B2.3.1 Limiting Factors

The basic need of shortest supply is the limiting factor- when the supply of this need is increased, the plant will grow faster until something else becomes its limiting factor

  • Light intensity
    • When insufficient, not enough energy to activate chlorophyll
    • Can keep lights on in greenhouse when dull or dark
  • Carbon dioxide
    •  When insufficient, cannot create glucose efficiently
    • Can add carbon dioxide to aid in greenhouse
  • Temperature
    • Can heat air in greenhouse when cold
    • Enzymes have optimum temperatures
      • If too low, rate of reaction is slow, hence slow growth
      • If too high, enzymes become denatured and do not work, decreasing rate

When the plant grower tends to these limiting factors, plants photosynthesise faster and create more glucose. They therefore grow faster and produce a greater crop yield- so the grower earns more when selling

4 of 4


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Photosynthesis and transpiration resources »