Question

Explain how apoplast route for phloem loading occurs.

Accepted Answer

Apoplast route:Protons are actively transported out of companion cellsProton gradient into companion cells createdProtons diffuse back into companion cells via co-transport carrier proteinThis allows co-transport of sucrose with protons into the companion cell  from source cellsSucrose can then diffuse into sieve tube elements down conc gradient

Front	Explain how apoplast route for phloem loading occurs.
Back	Apoplast route: Protons are actively transported out of companion cells Proton gradient into companion cells created Protons diffuse back into companion cells via co-transport carrier protein This allows co-transport of sucrose with protons into the companion cell from source cells Sucrose can then diffuse into sieve tube elements down conc gradient

Companion Cells Protons Apoplast Gradient Diffuse Co Transport Sucrose