diffusion Flashcards
what is the definition of diffusion?
Diffusion is the spreading out of particles resulting in a net movement from an area of higher concentration to an area of lower concentration.
what do cells need oxygen for?
how do we provide the oxygen needed for this process?
cells need oxygen for respiration which is carried out by mitochondria
what level of concentration of oxygen are cells surrounded by?
cells are surrounded by a high concentration of oxygen.
where is oxygen transported from?
oxygen is transported in the bloodstream from the lungs
explain the concentration of the outside and inside of the cell before diffusion takes place
their is a higher concentration of oxygen around the cell and a lower concentration of oxygen inside the cell
what is the first stage of diffusion?
the oxygen molecules move into the cell by diffusion from an area of higher concentration to an area of lower concentration.
what process is the oxygen used to generate?
what gas does this produce?
the oxygen is used to generate energy in respiration and this produces the waste gas carbon dioxide
when the oxygen is used to generate energy in respiration and this produces the waste gas carbon dioxide, explain the concentration levels of this.
we have a higher concentration of carbon dioxide inside the cell than outside
when the high concentration of carbon dioxide is inside the cell, what is the next stage of diffusion that occurs?
the high concentration of carbon dioxide is diffused out of the cell.
what is urea?
urea is a molecule that diffuses out of cells
it is a waste product produced inside cells. It diffuses out of the cells into the blood plasma and is excreted by the kidneys.
what are the 3 main factors that affect the rate of diffusion.
- the difference in concentration - the concentration gradient
- Temperature - the higher the temperature, the greater the rate of diffusion
- The surface area of a membrane - the larger the surface area of a cell membrane, the greater the rate of diffusion.
explain the concentration gradient
the greater the concentration gradient, the faster diffusion takes place
how does the temperature affect the rate of diffusion
the higher the temperature, the greater the rate of diffusion
This is because,
the particles have more kinetic energy and are moving faster!
molecules move in and out of cells by diffusion, give an example for this
oxygen diffuses into cells and carbon dioxide diffuses out
