BIO203H5 : Ch. 37 Book Review Guide. Extremely Detailed
Document Summary
Stomata are open during the day so that gas exchange can occur between the atmosphere and the cells inside the leaf. While stomata are open so that gas exchange can take place, the moist interior of the lead is exposed to the dry atmosphere: as a result, large quantities of water evaporate from the leaf"s surface. Water loss is a side effect of photosynthesis. The evaporation can actually be beneficial under some conditions because it cools the plant, just as sweating cools your body. Loss of water via evaporation from the aerial parts of a plant is called transpiration. Plants replace water that is lost from leaves with water that is absorbed by roots. Water moves from the roots to the leaves passively. Movement occurs because of differences in the potential energy of water. Water potential indicates the potential energy that water has in a particular environment compared with the potential energy of pure water.
