- The phloem is responsible for the transport of sugars (mainly in the form of sucrose), amino acids, and other organic compounds produced through photosynthesis in the leaves.
- Phloem cells are living and have a more complex structure, consisting of sieve-tube elements and companion cells.
- The transport in the phloem is bidirectional; it moves both up and down the plant.
- The movement of sap (sugar-rich water) in the phloem is facilitated by the pressure flow mechanism.
- Sugars are actively loaded into the sieve-tube elements in source areas (like leaves), creating a high osmotic pressure.
- This high pressure pushes the sap toward areas with lower pressure (sinks), such as roots, where the sugars are either stored or used for growth.