Describe how sucrose is loaded into the phloem (3)

Hydrogen ions are pumped out of companion cells using ATP.This creates a high concentration of hydrogen ions outside of the companion cell. H+ ions diffuse down their concentration gradient back into the companion cell with sucrose through a co-transporter. Sucrose diffuses down its concentration gradient into the sieve tube elements through the plasmodesmata.

Answered by Divyadharshini R. Biology tutor

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