Mineral Salts: Functions, Osmosis, and Trace Elements

Posted on Jan 11, 2025 in Biology

Mineral Salts: Composition and Function

Mineral salts are dissociated into ions (anions and cations) and are part of the intracellular and extracellular media.

Functions of Dissolved Salts

  1. Regulation of salinity: Ion concentrations vary across cellular compartments and must be regulated.
  2. Regulation of electric membrane potential.
  3. Regulation of enzymatic activity: Enzymes require specific conditions to function.
  4. Adjustment of pH: pH is a parameter dependent on biological activity within the cell.
  5. Regulation of osmotic pressure and cell volume.

Dissolution Buffers

These are solutions inside or outside the cell that regulate pH, maintaining it relatively constant. Examples include: Phosphate buffer (H2PO4) inside the cell and bicarbonate buffer (H2CO3) outside the cell.

Osmosis

Osmosis is the passage of a solvent from a dilute solution to a more concentrated one through a semipermeable membrane. This membrane allows solvent passage but not solute. The pressure exerted by water on the membrane is called osmotic pressure. Osmosis is a passive transport process that does not require energy and is crucial for cell hydration.

Cellular Environments

There are three types of cellular environments:

  • Isotonic medium: The intracellular and extracellular concentrations are equal, so there is no net water movement.
  • Hypertonic medium: The salt concentration outside the cell is greater than inside, causing water to leave the cell and decrease its volume (plasmolysis).
  • Hypotonic medium: The salt concentration inside the cell is greater than outside, causing water to enter the cell and increase its volume (turgor).

Precipitated Salts

These salts are insoluble in water and exist in solid form. They are mainly associated with protein-type macromolecules. Their primary function is to provide protection or support structures in organisms. Common examples include: silicates (spicules of sponges), calcium carbonate (shells of marine protozoans), and phosphates (mineral matrix of bone tissue in vertebrates).

Trace Elements and Their Roles

Iron: Essential for oxygen transport in red blood cells. Deficiency can lead to fatigue and respiratory problems.

Copper: Stimulates the immune system.

Chromium: Enhances insulin action and promotes glucose entry into cells.

Iodine: Part of thyroid hormones, influencing growth and maturation.

Manganese: Important for bone health and reproductive functions.

Selenium: An antioxidant that supports muscle function, the cardiovascular system, and prevents cataracts.

Zinc: Involved in hormone function, growth, insulin production, psychological function, sperm formation, and immune defense.

Cobalt: Component of vitamin B12, helps regulate blood pressure, dilates blood vessels, and promotes glucose binding in tissues.

Fluoride: Prevents tooth decay and slows osteoporosis.

Lithium: Acts on the nervous system and is useful for heart problems.

Nickel: Supports growth and combats anemia and infectious diseases.

Silicon: Increases elasticity and bone strength, slows aging, and balances the nervous system.