Questions:

Q1. Which of the following uses energy to transport molecules or ions against their concentration gradient?  

1. Voltage-gated Na⁺ channel
2. Acetylcholine receptor
3. Glucose transporter
4. ATP-ADP transporter
5. Na⁺/K⁺-ATPase

Q2. A membrane-spanning transporter protein that is also characterized as a "symporter" would be involved in which one of the following transport processes? 

1.  Simple transport (e.g., lactose via Lac permease)
2.  Simultaneous transport of one type of molecule into the cell and a different molecule out of the cell (e.g., Na⁺ “pump” to move Na⁺ out of the cell)
3. Transport of potassium ions into the cell without any other ion or molecule being transported in any direction
4. Unidirectional transport into the cell of only one type of molecule (found in very low concentration in the periplasm) using the ATP-driven ABC translocation system

Q3. The sodium-potassium pump passes 

1. more Na⁺ out than K⁺ in
2. K⁺ out and Na⁺ in on a one-for-one basis
3. Na⁺ out and K⁺ in on a one-for-one basis
4. K⁺ and Na⁺ in the same direction