Question

How does the passive movement of ions occur in apoplasts?

Answer 1

Passive movement of ions:

1. Ion movement is passive and happens via the apoplast route.
2. The apoplast route is the flow of ions between cells through the outside or free space (space outside the cell membrane).
3. Ion uptake via ion channels is a passive process that does not require any energy (transmembrane proteins).
4. The second phase is active, during which ions are steadily absorbed into the cellular matrix's inner region. This is referred to as the symplast route (active process).
5. In the first stage, there is a passive initial rapid uptake of ions into the apoplast, the cell's "free space" or “outside space.”
6. The ions are slowly absorbed into the "inner space" of the cells' symplast during the second phase of uptake. The transmembrane proteins known as ion channels, which serve as specific pores, are often responsible for the passive transport of ions into the apoplast.
7. However, the entrance or exit of ions from the symplast necessitates the use of metabolic energies. The inward movement of ions into the cells is referred to as influx, and the outward movement is efflux.