For Each of the Following Sentences, Fill in the Blanks

For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below.Not all words or phrases will be used; each word or phrase should be used only once.
$\begin{array}{lll}\text { antiport } & \text { coupled } & \text { membrane potential } \\\text { ATP hydrolysis } & \text { electrochemical } & \text { symport } \\\text { concentration } & \text { light-driven } & \text { uniport }\end{array}$

For an uncharged molecule, the direction of passive transport across a membrane is determined solely by its __________ gradient.On the other hand, for a charged molecule, the __________ must also be considered.The net driving force for a charged molecule across a membrane therefore has two components and is referred to as the __________ gradient.Active transport allows the movement of solutes against this gradient.The transporter proteins called __________ transporters use the movement of one solute down its gradient to provide the energy to drive the uphill transport of a second solute.When this transporter moves both ions in the same direction across the membrane, it is considered a/an __________; if the ions move in opposite directions, the transporter is considered a/an __________.