Indicate Which Characteristic of a Mediated-Transport System Is Referred to in Each

Essay

Indicate which characteristic of a mediated-transport system is referred to in each item by filling in the blank using the following answer code.
$\begin{array}{lr}\text { 1. Carrier can handle substance } X \text { but not substance } Y \text {. }&\text { specificity }\_\_\_\\\text { 2. In the presence of substance } Z \text { there is a decreased rate }\\\text { of entry of substance } X&\text { competition }\_\_\_\\\text { 3. The concentration of substance } \mathrm{X} \text { outside the cell }\\\text { continues to increase but the rate of substance X's transport }\\\text { into the cell remains constant. }&\text { saturation }\_\_\_\end{array}$