1. “…beneath the clothes, we find a man... and beneath the man we find... his... nucleus.”-Nacho Libre Reference Text - Modern Biology Chapter 2 / pgs. 30-42

2. It is the flow of energy that the Biologists seek to understand when they study the chemistry of living things…

3.  The amount of energy in the universe remains the same.  Energy can change forms  Energy flows from the sun through all living things

4. ENERGY What is ENERGY? Scientists define ENERGY as the ability to do work or cause change. Energy in Living Things: As energy flows through a living organism, it is converted from one form to another.

5. Atoms and molecules are in constant motion (kinetic energy). state of matter. Amount of movement determines the state of matter. States of Matter 1. Solid 2. Liquid 3. Gas

6.  Particles linked together  Has a definite shape  Particles vibrate (little kinetic energy) Example: ice  Particles not as tightly linked.  Can flow, conform to the shape of the container.  Definite volume, not definite shape. Example: water  Particles moving rapidly (lots of energy)  Fill volume of any container.  No fixed volume or shape Example: steam (water vapor) ***To cause a substance to change state, thermal energy (heat) must be added to or removed from a substance***

8. Chemical Reaction Chemical Reaction - breaking or forming chemical bonds. Chemical Equation right. Chemical Equation - represent chemical reactions; reactants are shown on the left, products are shown on the right. - Na + Cl ----  NaCl Reactants Products Reactants Products This chemical reaction is breaking chemical bonds, rearranging and forming new bonds …

9. CHEMICAL REACTIONS Living organisms undergo thousands of CHEMICAL REACTIONS as part of their life processes

10. For most chemical reactions to begin, energy must be added to the reactants. Activation Energy Activation Energy – the amount of energy needed to start a chemical reaction SPEEDS IT UP! Catalysts – A chemical substance that reduces the amount of activation energy needed to start a chemical reactions - SPEEDS IT UP!

11. Enzymes are an important class of catalysts in living things (usually a protein)