Question

Understand the first two laws of thermodynamics, and apply them to living systems.

Answer 1

The First law states that " energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another "

In plant photosynthesis, the energy is channeled by the sun. Light energy absorbed by cells in leaves is converted to chemical energy. The chemical energy is stored as glucose, which is used to form complex carbohydrates necessary to build plant mass. The chemical energy in plants ( carbohydrates and fats ) is converted to ATP which is further used in metabolism by cells.

The Second Law of Thermodynamics states " when energy is transferred, there will be less energy available at the end of the transfer process than at the beginning.

In photosynthesis not all of the light energy is absorbed by the plant. Some energy is reflected and some is lost as heat in the eneviroment. The higher up an organism is on the food chain, the less available energy it receives from its food sources. Much of this energy is lost during metabolic processes.