1. BIOLOGY
Unit 3 Notes:
Energy & Living
Things

2. (1) Why Is Energy
Needed?
• To do work.
• To do all life processes:
– Grow
– Reproduce
– Metabolize and Excrete
– Respond
– Maintain Homeostasis

3. (2) Types of Energy
• Chemical Potential Energy:
– Stored energy in the bonds of
molecules.
• Kinetic Energy:
– Energy of motion.
– Energy being used right now in
reactions.

4. (3) Cycling of Energy and
Matter
• Both energy and matter and continuously
cycled throughout the environment.
• When molecules are broken down, energy is
released to another system.
• When molecules are produced
(bonded together), energy is stored for later.

6. (4) ATP and ADP
• Both store energy in their phosphate bonds.
• ATP = Adenosine Triphosphate
– Contains 3 phosphates.
– Can RELEASE energy if you remove the 3rd
phosphate.
• ADP = Adenosine Diphosphate
– Contains 2 phosphates.
– Can STORE energy if you add a 3rd phosphate.

8. (5) Chemical Formulas To
Know
• CO2 = Carbon Dioxide (gas)
• H2O = Water (vapor / gas)
• C6H12O6 = Glucose
• O2 = Oxygen (gas)
• Sunlight = Sunlight

9. (6) Chemical Equation
Review
• Reactants:
– On the left side of equation.
– Starting ingredients or molecules for the
reaction.
• Products:
– On the right side of the equation.
– What you make at the end of the reaction.