Question

${\mathrm{Na}}^{+}-K^{+}$ pumps work by

• A. transporting 3${\mathrm{Na}}^{+}$ in and 2$K^{+}$ out of the cell membrane
• B. transporting 2${\mathrm{Na}}^{+}$ out and 3$K^{+}$ into the cell membrane
• C. transporting 3${\mathrm{Na}}^{+}$ out and 2$K^{+}$ into the cell membrane
• D. transporting 2${\mathrm{Na}}^{+}$ in and 3$K^{+}$ out of the cell membrane

Answer 1

The correct option is C transporting 3${\mathrm{Na}}^{+}$ out and 2$K^{+}$ into the cell membrane

Active transport is highly specific to the molecules that are being transported. ATP (energy currency of the cell) is consumed in this process as the transportation occurs against the concentration gradient (from a region of lower concentration to a region of lower concentration). It is sensitive to inhibition (inhibitors usually target the side chain of proteins). It generally occurs with the help of pumps. Pumps are ATP consuming membrane transport proteins that transport molecules across the membrane against their concentration gradient. For e.g. ${\mathrm{Na}}^{+}-K^{+}$ pumps function by transporting 3${\mathrm{Na}}^{+}$ ions out of the membrane in exchange for bringing 2$K^{+}$ ions into the membrane.