translocation

• what is translocation?

  transport of assimilates in the phloem/ transport of organic substances in a plant
• what is the liquid that is being transported within sieve tubes called?

  phloem sap
• what does phloem sap consist of?

  sugars (mainly sucrose), water, amino acids, hormones, minerals, and other dissolved substances
• where might sources of assimilates be?


  green leaves and green stem

  storage organs

  food stores in seeds
• how are green leaves and stems sources?

  photosynthesis produces glucose which is transported as sucrose, as sucrose has less of an osmostic effect than glucose
• how are storage organs sources?

  for instance tubers and tap roots unloading their stored substances at the beginning of a growth period
• what are sinks?

  where the assimilates are required
• where might sinks be?

  meristems that are actively dividing

  roots that are growing or actively absorbing minerals

  any part of the plant where the assimilates are being stored such as storage organs, developing seeds or fruits
• What type of process is the loading and unloading of sucrose from the source to the phloem?

  an active process