Application of 1st law of thermodynamics

• A living system is an open system where matter and energy are exchanged.
• Some of this energy is used in useful work and some is returned to the surroundings as heat to produce molecules.
• Leaves absorb energy from surroundings in two ways; direct incident radiation from the sun and infrared radiation from the surrounding. Some of the energy is returned as infrared radiation and the rest is used in photosynthesis i.e. energy stored in energy emitted by the leaf + energy stored by the leaf
• Sunlight is the ultimate source of energy. Thermonuclear reaction in the sun produces energy that is transmitted to the earth as light and converted into chemical energy by plants 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 moves a body at the cost of potential energy.