Translocation

Translocation is the term which is used to describe the transport of soluble organic compounds such as sugars, within a plant

These are the substances the plant has made itself, most likely by photosynthesis in the leaves.

These will be transported by the Phloem

Assimilates are transported in Sieve tube elements in the phloem. These sieve tubes work with companion cells to achieve translocation

The immediate difference from the Xylem is that the phloem cannot use mass flow passively and how to use energy

This happens due to active loading

Here sucrose is loaded into the sieve element and this decreases the water potential of the sap at the leaf and therefore water follows

A source is where sucrose is loaded into the Phloem and a sink is where sucrose is unloaded from the phloem