BIOL 206 Lecture Notes - Lecture 19: Water Balance, Water Column, Stoma
Document Summary
Root pressure- rare + change in si from the soil. Active transport of ions into the roots creates large solute gradients. Thus -change in si inside roots: solutes in soil makes water potential negative, root xylem has lower si because of more ions/solutes, as water xylem due to osmosis, pressure potential increases. As increases pressure, pushes water up-root pressure: transport cohesion tension. Water vapor diffuses from leaf cell surfaces to surrounding air. A water column extends from the root to this interface, and is held together by cohesion/ because of water molecules. The tension that forms pulls water though the plant: water column created when plant is young. Xulem venation brings water close to every ce. l in the elaf. Leaving xylem: transportation helps keeps plant cool. Having water plant plant does this: competing issues in control of water, only guard cells have chloroplast.
