Movement of Substances (5078 syllabus)

Mo v ement of Subst ances 1 Movement of Substances Diffusion: net movement of particles from region of higher conc to region of lower conc down the conc gradient Osmosis: net movement of water molecules from region of higher water potential o region of lower water potential Turgidity Plant cell turned turgid. Solution X has a higher water potential than the plant cell water molecules move from solution x to the plant cell through the partially permeable cell surface membrane by osmosis causing the vacuole to expand in size and hence, the tugidity Flaccidity Plant cell is flaccid. Solution Y has a lower water potential than the plant cell water molecules move from the plant cell to solution Y through the partially permeable cell surface membrane by osmosis causing the vacuole to shrink in size and hence the flaccidity. Plasmolysis

Mo v ement of Subst ances 2 Plant cell is plasmolysed. Solution Z has a much lower water potential than the plant cell water molecules move from the plant cell to solution z through the partially permeable cell surface membrane by osmosis. causes the vacuole to shrink in size, the cell surface membrane pulling away from the cell wall and hence, the plasmolysis. RBC bursting Solution x has a higher water potential than the red blood cell water molecules move from solution x into the red blood cell through the partially permeable cell surface membrane by osmosis causing the red blood cell to expand in size and hence, the bursting of the red blood cell occurs. Solution y has a lower water potential than the red blood cell water molecules from the red blood cell moves to solution y through the partially permeable cell surface membrane by osmosis causing the red blood cell to shrink in size due to dehydration, hence the crenation of the red blood cell.