TRANSPORT IN CELLS Flashcards
Diffusion
The net movement of particles from a high to low concentration
Concentration gradient
The difference in concentration between two areas, substances or solutions
Surface area to volume ratio
This is calculated by dividing the SA by the VOL(SA:V) .it decreases as the objects gets larger.
Exchange surface
A surface across which materials are exchanged. In multicellular organisms these have adaptations to increase the efficiency of exchange. E.g large surface area.
Alveoli
The tiny air sacs in the lungs which increase the surface area for exchange of gasses
Villi
The finger like projections from the lining of the small intestine which increase the surface area for exchange of gasses
Root hair cell
The cell on the root of a plant with microscopic hairs Which increase the surface area of the absorption of water and nutrients from the soil
Guard cells
These cells surround the stomats in the leaves of plants and control their opening and closing
Stomata
Opening of the leaves of plants which allow gasses to enter and leave the plants.
Spongy mesophyll
A layer of cells found in the leaves of plants. These are rounded cells that provide air spaces to increase the surface area of the exchange of gasses
Osmosis
The diffusion of from a dilute solution to a concentration solution through a partially permeable membrane
Solute
The solid that dissolves in a solvent to form a solution
Solvent
The liquid in which a solute dissolves to form a solution
Partially permeable membrane
A membrane that allows only certain substances to pass through
Urea
The waste produce formed by the breakdown of excess amino acids in the liver
