Excretion, plant transport and the kidney Flashcards
What is osmosis?
Osmosis is the net diffusion of free water molecules from an area of high water concentration to an area of low water concentration across a partially permeable membrane.
What are free water molecules?
When the sugar dissolves, water molecules are attracted to the sugar molecules. These water molecules are now not considered free.
What is a partially permeable membrane?
A partially permeable membrane is a membrane that only allows certain particles through. In Osmosis, the partially permeable membrane only lets free water molecules through.
What is water potential?
The concentration of free water molecules in a solution. Water moves (by osmosis) from an area of high water potential to one of low water potential.
What is an isotonic solution?
The solution outside the cell has the same water potential as inside the cell - no net movement.
What is a hypotonic solution?
The solution outside the cell has a higher water potential than inside the cell - net movement of free water molecules into the cell.
What is a hypertonic solution?
The solution outside the cell has a lower water potential than inside the cell - net movement of free water molecules out of the cell.
Why do plants wilt?
Plants wilt because there is not enough water to fill their cells and therefore the cytoplasm shrinks from the cell wall.
What is active transport?
Active Transport is the movement of molecules from n area of low concentration to an area of high concentration using ATP.
How is glucose transported?
Active transport.
