Inracellular concentration of K+ is
**Core Concept**
Intracellular concentration of potassium (K+) is an essential aspect of cellular physiology, particularly in maintaining the resting membrane potential and regulating various cellular processes. The intracellular concentration of K+ is significantly lower compared to the extracellular concentration.
**Why the Correct Answer is Right**
The intracellular concentration of K+ is approximately 150 mmol/L, which is achieved through the action of the Na+/K+-ATPase pump. This pump actively transports three sodium ions out of the cell and two potassium ions into the cell, utilizing ATP as an energy source. This process maintains the low intracellular K+ concentration and high extracellular K+ concentration, which is essential for the proper functioning of the nervous system and muscle contraction.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct concentration or mechanism of potassium transport.
**Option B:** This option is incorrect because it does not accurately represent the intracellular concentration of potassium.
**Option C:** This option is incorrect because it does not provide any relevant information about the intracellular concentration of potassium.
**Clinical Pearl / High-Yield Fact**
The Na+/K+-ATPase pump is essential for maintaining the resting membrane potential and is often targeted in various diseases, such as hypertension and cardiac failure. It is also a common site of action for various medications, including digitalis and beta-blockers.
**Correct Answer: C. 150 mmol/L**