Question 17 (0.75 points) At rest, this transmembrane protein plays a critical role in maintaining the proper balance of electrolytes on opposite sides of a neural membrane: cytochrome c oxidase voltage gated calcium channel sodium potassium (Na+/K+) /K+) pump ATP synthase

The correct answer is **sodium potassium (Na+/K+) pump**.<br /><br />Here's why:<br /><br />The sodium-potassium pump (Na+/K+ pump) is a transmembrane protein that actively transports sodium ions (Na+) out of the cell and potassium ions (K+) into the cell. This process requires energy in the form of ATP. This active transport is crucial for maintaining the resting membrane potential of neurons, which is the electrical difference across the cell membrane when the neuron is not firing. This potential is essential for the neuron's ability to generate and transmit electrical signals.<br /><br />The other options are incorrect for the following reasons:<br /><br />* **Cytochrome c oxidase:** This is an enzyme involved in the electron transport chain in mitochondria, which is part of cellular respiration, not directly involved in maintaining resting membrane potential.<br />* **Voltage-gated calcium channel:** These channels open in response to changes in membrane potential and allow calcium ions to flow into the cell. They are important for signal transduction and neurotransmitter release, but not for maintaining the resting membrane potential.<br />* **ATP synthase:** This enzyme synthesizes ATP using the energy from a proton gradient. While ATP is used by the Na+/K+ pump, ATP synthase itself doesn't directly maintain the electrolyte balance across the neural membrane.<br />