The atoms and molecules on the Earth cycle among the living and nonliving components of the biosphere.

Some of the water molecules which are used in photosynthesis are returned to the environment.

The change of water from the liquid to the gas state is called evaporation, while the water lost to the atmosphere by the activities of plants is referred to as transpiration water loss.

This water vapor eventually condenses to form clouds, and is returned to the earth as precipitation.

This process is called the water cycle.

The processes of cell respiration and excretion also releases some water to the environment as well.

The Water Cycle