Describe exchange contact theory about absorption and transport of mineral salts
Exchange contact theory is a scientific concept that explains how ions are absorbed and transported across biological membranes. According to this theory, ions are exchanged between a soluble ion in the external medium and an insoluble ion in the membrane at the point of contact.
In the context of absorption and transport of mineral salts, exchange contact theory suggests that mineral salts are absorbed by cells through a process of ion exchange. When mineral salts in the external medium come into contact with the cell membrane, the ions in the mineral salts are exchanged with ions in the membrane. This allows the mineral salts to be absorbed into the cell and transported across the membrane.
For example, when a plant root comes into contact with soil containing mineral salts such as potassium or calcium, the ions in the soil are exchanged with ions in the root cell membrane. This enables the plant to absorb the mineral salts and transport them to other parts of the plant for growth and metabolism.
Overall, exchange contact theory provides a framework for understanding how mineral salts are absorbed and transported in biological systems through the exchange of ions at the cell membrane.