Overview
This lecture explains the main types of energy important in biology—kinetic, potential, and chemical energy—and how energy can transform between these forms.
Introduction to Energy
- Energy is defined as the ability to do work or cause change.
- In biology, energy comes in different forms including light, heat, and electricity.
- Energy cannot be lost but it can be converted from one form to another.
Kinetic Energy
- Kinetic energy is energy associated with the motion of objects.
- Examples include a moving wrecking ball, a bullet, or a person walking.
- Thermal energy, a type of kinetic energy, is due to the random movement of atoms or molecules.
- Temperature measures the average thermal energy in a group of molecules.
- Transfer of thermal energy between objects is called heat.
Potential Energy
- Potential energy is stored energy due to an object's position or structure.
- A motionless wrecking ball held above the ground has potential energy from its position.
- Chemical energy, stored in chemical bonds, is a form of potential energy.
- Examples of potential energy include water behind a dam and a person ready to skydive.
Energy Conversions
- Energy can switch between kinetic and potential forms (e.g., falling wrecking ball gains kinetic as it loses potential energy).
- Chemical energy in gasoline converts to kinetic and thermal energy in a moving car.
- In living organisms, energy in ATP (potential) powers muscle movement (kinetic).
Key Terms & Definitions
- Energy — Ability to do work or cause change.
- Kinetic Energy — Energy of motion.
- Thermal Energy — Kinetic energy due to movement of molecules or atoms.
- Heat — Transfer of thermal energy from one object to another.
- Temperature — Measure of average thermal energy in a system.
- Potential Energy — Stored energy due to position or structure.
- Chemical Energy — Potential energy stored in chemical bonds.
Action Items / Next Steps
- Review examples of energy conversions in daily life.
- Study the next lesson: First Law of Thermodynamics.