Application of 1st law of thermodynamics

• A living system is an open system where the matter and energy both are exchanged.
• Some of this energy is used in useful work and some is returned to the surrounding as heat to produce molecules.
• Leaves absorb energy from surrounding in two ways; direct incident radiation from the sun and infrared radiation from the surrounding. Some of the energy is returned back as infrared radiation and rest is used in photosynthesis i.e. energy stored in leaf=energy emitted by leaf + energy stored by leaf
• Sunlight is ultimate source of energy. thermonuclear reaction in the sun produces energy that is transmitted to earth as light and converted into chemical energy by plant and certain microorganisms
• ATP is the universal carrier of metabolic energy linking catabolism and anabolism.
• Potential energy is storage energy present in the body at rest. While kinetic energy of motion that moves a body at the cost of potential energy.