Practise active-transport questions by explaining ATP-driven ion pumping against concentration gradients and interpreting sodium-potassium concentration tables.
Calcium is absorbed from food in the human gut by both active and passive processes. Outline active transport, including the benefits of the process.
| a | moved against a concentration gradient/lower to higher concentration |
| b | energy/ATP required/used |
| c | pump/carrier «protein» «carries out active transport» |
| d | absorption «by active transport» into a cell is possible even if exterior concentrations are «very» low OR allows all/nearly all of/more of the substance/calcium to be absorbed «whereas diffusion can only even out concentrations» OR unidirectional/allows the direction of movement to be controlled OR allows a concentration gradient to be built up/potential energy to be stored/membrane potential to be generated/maintained OR allows a specific concentration to be maintained «in a cell» |