Movement in the Phloem (AQA A-Level Biology): Flashcards

Transport of organic molecules & mineral ions from one part of plant to another

Elongated cells arranged end-to-end with perforated sieve plates

Provide metabolic support & control loading/unloading of substances

Locations where sugars produced during photosynthesis (typically leaves)

Areas where sugars used immediately or stored (roots, fruits, growing tissues)

Sucrose, amino acids, inorganic ions (K, Cl, phosphate, Mg)

Bulk movement of solutions through pressure differences in phloem

$H^+$ pumped out (using ATP), sucrose co-transported back with $H^+$

High pressure at source, low pressure at sink drives flow

Sucrose actively removed, used for respiration or converted to starch for storage