Transport of Sucrose in Plants (WJEC GCSE Biology)

Phloem & the Transport of Sucrose

• Photosynthesis produces glucose, which can then be converted into sucrose for transport around the plant

  • Glucose can also be converted into other substances, such as amino acids

• Sucrose is transported from the photosynthetic parts of plants to the places where it is needed

• Sucrose transport takes place in the phloem 

  • The movement of sucrose in the phloem is sometimes referred to as translocation

• When sucrose leaves the phloem it can be converted into other substances, e.g.

  • Glucose for respiration

  • Starch for storage

• Phloem tissue is adapted to allow the easy transport of sucrose, e.g.

  • The end walls of phloem cells contain pores to allow sucrose to pass through

  • Neighbouring cells, known as companion cells, contain many mitochondria to actively transport sucrose into the phloem

Phloem structure diagram

Sucrose is transported from the site of photosynthesis in the phloem