Sodium in biology

Sodium in Biology

Sodium is a chemical element with the symbol Na (from Latin "natrium") and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. In biology, sodium is an essential mineral that plays a key role in many bodily functions.

Role in the Body

Sodium is one of the primary electrolytes in the body. All four cationic electrolytes (sodium, potassium, magnesium, and calcium) are found in the blood at concentrations that are set by the kidney. Sodium is the most prominent cation in extracellular fluid: it is responsible for one-half of the osmotic pressure gradient that exists between the interior of cells and their surrounding environment. People eating a typical diet consume between 2 and 4 grams of sodium per day.

Sodium-Potassium Pump

The sodium-potassium pump is an essential cellular membrane protein that functions by pumping out three sodium ions and taking in two potassium ions. This mechanism preserves the electrochemical gradient that aids in nerve impulse transmission and muscle contraction.

Sodium Channels

Sodium channels are integral membrane proteins that form ion channels, conducting sodium ions (Na+) through a cell's plasma membrane. They are classified according to the trigger that opens the channel for such ions, i.e., either a voltage-change ("voltage-gated sodium channels") or a chemical signal ("ligand-gated sodium channels").

Sodium in Diet

Sodium is a necessary nutrient in the human diet, as it aids in nerve and muscle function and is essential for maintaining fluid balance. However, excessive sodium intake can lead to hypertension and cardiovascular disease.

See Also

• Potassium in biology
• Calcium in biology
• Magnesium in biology

References

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