This movement is against the concentration gradient so the transport proteins require an energy supply. Energy is provided by the breakdown of ATP inside the cell. This diagram shows molecules ...

Pure water has the highest water concentration. A concentration gradient exists when there is a region of high concentration leading to a region of low concentration: ...

WHEN a concentration gradient in a vertical column of solution, for example, an ultracentrifuge cell, is investigated by a refraction method, it is desirable to obtain a diagram relating the ...