1. Unit 2 Metabolic Processes

2. Metabolism Living organisms must constantly capture, store and use energy to carry out the functions of life. At any given instant an organism is: breaking down macromolecules (catabolic reactions) to release energy synthesizing macromolecules (anabolic reactions) which requires energy The sum of all anabolic and catabolic processes in a cell or organism is called METABOLISM.

3. Energy Energy: the capacity to do work Work: to change or move matter Kinetic Energy: energy of motion Moving objects perform work by causing other matter to move Potential Energy: stored energy Ex. chemical energy in bonds, potential energy in gradients

4. Energy Transfer Chemical energy stored in food molecules must be transformed before we can use it When a chemical reaction occurs in your body, some of the energy released is used Ex. Mechanical energy (movement) Some is transformed into heat or other forms When chemical reactions occur, the energy available to do work decreases, as more of it is transformed into unusable heat

5. Are the following anabolic or catabolic? protein synthesis digestion photosynthesis cellular respiration

6. Making and breaking bonds Chemical reactions always involve energy changes Most reactions also include the breaking and making of bonds Energy is released when a bond is broken and absorbed when a new bond is made.

7. Exergonic Reactions (aka Exothermic) Potential energy of reactants is greater than potential energy of products Energy is released after reaction

8. Endergonic Reactions (aka Endothermic) Potential energy of reactants is lower than potential energy of products Energy is put into the system

9. Are the following endergonic or exergonic? protein synthesis digestion photosynthesis cellular respiration

10. Homework How is energy important to a living organism? A molecule of glucose has potential energy What does this mean to a cell? Where is the energy in the glucose molecule? You turn on a CD player and the disc begins to rotate. How is this an example of energy transformation? Define and provide examples of exergonic and endergonic reactions