movement/uptake of water and mineral ions into root hair cells extras

root pressure

when hydrostatic pressure is generated due to water moving from the endodermal cells of the root and into the xylem by osmosis, and forces water a small distance up the xylem

effects of cyanide to root pressure

• casparian strip stops apoplast pathway/forces ions into the symplast pathway

• movement of ions into xylem require acitve transportation

• cyanide is a respiratory inhibitor/prevents cells from respiring/stops ATP synthesis

• lower water potential gradient reduces root pressure, so water doesn’t enter xylem by osmosis

why does the plant need to control entry of mineral ions into xylem

some mineral ions are toxic if they are absorbed and accumulate inside the plant tissue

how does plant tissue ensure toxic ions cannot enter its cells

doesn’t have suitable/specific carrier proteins for those ions

why do plants need to absorb nitrates from soil

to produce DNA or ATP

two features of root hair cell for uptake of water and mineral ions

• large surface area

• lots of mitochondria

list of other mineral ions and their uses

phospahate ions - for cell membranes

magnesium ions - for chlorophyll