Water and Mineral Acquisition

Water accounts for over 80% of the mass of most plants. It is essential for photosynthesis, metabolism, and nutrient transport.

Inorganic nutrients are also essential for growth and reproduction. For example, nitrogen is a building block of key biomolecules such as amino acids, while potassium is critical for the opening and closing of stomata.

How do plants absorb large amounts of water and nutrients efficiently?

Most plants take in water and minerals from the soil through their roots.

Roots release hydrogen ions and carbon dioxide. Carbon dioxide reacts with water to form carbonic acid. This acid then breaks down into bicarbonate and hydrogen ions.

Hydrogen ions bind to negatively charged soil particles and release positively charged ions, such as potassium, into the soil solution. This process is called cation exchange and makes nutrients available to the plant.

Root architecture and branching patterns help make water and nutrient uptake efficient.

Some epidermal cells form tiny root hairs that come into contact with the soil. These specialized cells have a large surface area. This feature helps water enter by osmosis, and nutrients enter through both passive and active transport.

Water