2(d) Movement of Substances Flashcards
Diffusion
The passive movement of molecules from an area of higher concentration to an area of lower concentration
Factors affecting diffusion
Temperature
* Molecules have more kinetic energy at high temperatures so they diffuse faster.
Concentration Gradient
* The greater the difference in concentrations, the faster diffusion will occur.
Surface Area to Volume ration
* The larger the SA:VOL the faster the diffusion will occur
Distance
* The longer the distance, the slower diffusion will be.
Osmosis
The movement of water from an area of higher water potential to an area of lower water potential acrosss a selectively-permeable membrane.
Turgid
When a cell or tissue is swollen from water uptake/holding too much water.
Flaccid
When a cell becomes soft due to the loss of water.
Active Transport
The movement of molecules form low to high concentration requiring energy in the form of ATP.