the concentration of Na, K, Ca in a cell in decreasing order is

Options

A. (a) K-Na-Ca
B. (b) K-Ca-Na
C. (c) Na-K-Ca
D. (d) Ca-K-Na

Answer

To determine the concentration of sodium (Na), potassium (K), and calcium (Ca) ions in a cell in decreasing order, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Ion Concentration in Cells**:
- In a typical cell, the concentrations of various ions differ between the inside (cytoplasm) and outside (extracellular fluid) of the cell.

2. **Identifying Key Ions**:
- The three ions we are focusing on are sodium (Na), potassium (K), and calcium (Ca).

3. **Analyzing Potassium (K)**:
- Potassium ions are found in higher concentrations inside the cell. This is crucial for maintaining the cell's resting membrane potential and is vital for nerve impulse transmission.

4. **Analyzing Sodium (Na)**:
- Sodium ions are predominantly found outside the cell. While they are important for action potentials, their concentration inside the cell is lower than that of potassium.

5. **Analyzing Calcium (Ca)**:
- Calcium ions are typically present in very low concentrations inside the cell compared to potassium and sodium. They play a significant role in signaling and muscle contraction but are mainly found in the extracellular fluid.

6. **Establishing the Order**:
- Based on the analysis, the order of concentration from highest to lowest inside the cell is:
- Potassium (K) > Sodium (Na) > Calcium (Ca)

7. **Final Answer**:
- Therefore, the correct order of concentration of Na, K, and Ca in a cell in decreasing order is:
- **K > Na > Ca**