T6 - Movement of Substances Flashcards
what happens when a cell becomes turgid
there is a higher water concentration outside the cell so water moves into the cell across the partially permeable membrane by the process of osmosis. The cytoplasm swells up and pushes on the cell wall
What is active transport?
The movement of molecules through a cell membrane from an area of low concentration to an area of high concentration that requires energy from respiration
what is one adaptation cells may have in order to carry out active transport and why
more mitochondria - increased respiration
Why is energy needed in active transport?
because the substance is going against the concentration gradient
What is diffusion?
The movement of particles from an area of high concentration to an area of low concentration.
gases that can pass in and out of cells by diffusion
oxygen and carbon dioxide
How does the concentration gradient affect the rate of diffusion?
diffusion is faster when there is a steeper concentration gradient
how does molecular size affect the rate of diffusion
the smaller the mass of the molecule, the faster it will diffuse
how does temperature affect the rate of diffusion
The higher the temperature, the faster the rate of diffusion
how does diffusion distance affect the rate of diffusion
the shorter the diffusion distance, the faster the rate of diffusion
why do cells need diffusion
so that oxygen and carbon dioxide can diffuse in and out of the cell allowing the cell to respire
diffusion is a passive process
it doesn’t require energy from respiration
What is osmosis?
the net movement of water particles from an area of high water concentration to an area of low water concentration across a partially permeable membrane
what happens when a cell becomes plasmolysed
there is a higher water concentration inside the cell so water moves out of the cell across the partially permeable membrane by the process of osmosis. The cytoplasm pulls away from the cell wall completely.
