1. What characteristics are common to all organisms?

2. Characteristics of Life: Living things… use energy, develop and grow, maintain organization and homeostasis, reproduce asexually or sexually, form populations that evolve, have DNA as the genetic code.

3. Why is water so important to life?

4. Extraordinary Properties of Water Cohesion –Water molecules stick together –Surface tension Adhesion –Water molecules cling to other solids –capillarity

5. Extraordinary Properties of Water High Specific Heat –Amount of heat that must be absorbed for 1g to change 1 o C for water = 1.00 cal/g/ o C Sp Heat of common liquids Liquid SpHt (cal/g/ o C) Ammonia 1.23 Water 1.00 Eth alc 0.60 Acetone 0.53 Olive oil 0.47 Mercury 0.03

6. Extraordinary Properties of Water High Heat of Vaporization –(change from liquid to gas) –Quantity of heat a liquid must absorb for 1g to be converted to the gas state for water = 576 cal/g Ht of Vap of some liquids Liquid Ht Vap (cal/g) Water at 37C 576 Ammonia 302 Eth alcohol 237 Acetone 125 Mercury 59

7. Extraordinary Properties of Water

8. Water is a versatile solvent –Ionic compounds dissolve in water –Covalent compounds rich in O or N dissolve in water

9. Extraordinary Properties of Water Adhesion and Cohesion High Specific Heat High Heat of Vaporization Expands when freezing Versatile Solvent

10. How does water do all this? What allows water to facilitate life at the cellular and global level?

12. Hydrogen Bonds A weak force of attraction between the H on one molecule and a highly electronegative atom on another molecule

13. Extraordinary Properties of Water Versatile Solvent-------due to polarity Adhesion and Cohesion---due to H bonds High Specific Heat --------due to H bonds High Heat of Vap. ---------due to H bonds Expands when freezing ---due to H bonds