1. The Extraordinary Properties of Water

2. Water
A water molecule (H2O), is made up of three atoms --- one oxygen and two hydrogen. H O 1

3. Water is Polar
In each water molecule, the oxygen atom attracts more than its "fair share" of electrons
The oxygen end “acts” negative
The hydrogen end “acts” positive
Causes the water to be POLAR
However, Water is neutral (equal number of e- and p+) --- Zero Net Charge

4. Hydrogen Bonds Exist Between Water Molecules
Formed between a highly Electronegative atom of a polar molecule and a Hydrogen
One hydrogen bond is weak , but many hydrogen bonds are strong

5. Interaction Between Water Molecules
Negative Oxygen end of one water molecule is attracted to the Positive Hydrogen end of another water molecule to form a HYDROGEN BOND

6. What are the Properties of Water?1

7. Quick Water Facts
At sea level, pure water boils at 100 °C and freezes at 0 °C.
The boiling temperature of water decreases at higher elevations (lower atmospheric pressure).
For this reason, an egg will take longer to boil at higher altitudes 1

8. Check Your Understanding
August Alsina (A2), Mt. McKinley and Poconos
Mt. McKinley: 20,322 ft
Poconos: 2,693 ft
In which place will A2 have to wait longer for his eggs to boil?

9. Properties of Water Cohesion Adhesion High Specific Heat
High Heat of Vaporization
Less Dense as a Solid 1

10. Cohesion
Attraction between particles of the same substance ( why water is attracted to itself)
Results in Surface tension (a measure of the strength of water’s surface)
Produces a surface film on water that allows insects to walk on the surface of water 1

11. Helps insects walk across water
Cohesion …
Helps insects walk across water

12. Jesus Christ Lizard

13. Adhesion Attraction between two different substances.
Water will make hydrogen bonds with other surfaces such as glass, soil, plant tissues, and cotton.
Capillary action- adhesion + cohesion; how water travels up thin tube
Example: transpiration process which plants and trees remove water from the soil, and paper towels soak up water. 1

14. Adhesion Causes Capillary Action
Which gives water the ability to “climb” structures

15. High Specific Heat
Amount of heat needed to raise or lower 1g of a substance 1° C.
Water resists temperature change, both for heating and cooling.
Water can absorb or release large amounts of heat energy with little change in actual temperature. 1

16. High Heat of Vaporization
Amount of energy to convert 1g of a substance from a liquid to a gas
In order for water to evaporate, hydrogen bonds must be broken.
As water evaporates, it removes a lot of heat with it. 1

17. High Heat of Vaporization
Water's heat of vaporization is 540 cal/g.
In order for water to evaporate, each gram must GAIN 540 calories (temperature doesn’t change oC).
As water evaporates, it removes a lot of heat with it (cooling effect). 1

18. Water is Less Dense as a Solid
Ice is less dense as a solid than as a liquid (ice floats)
Liquid water has hydrogen bonds that are constantly being broken and reformed.
Frozen water forms a crystal-like lattice whereby molecules are set at fixed distances. 1

19. Water is Less Dense as a Solid
Which is ice and which is water? 1

20. Water is Less Dense as a Solid
Ice 1

21. Homeostasis
Ability to maintain a steady state despite changing conditions
Water is important to this process because:
a. Makes a good insulator
b. Resists temperature change
c. Universal solvent
d. Coolant
e. Ice protects against temperature extremes (insulates frozen lakes) 4

22. Check Your Understanding
In this property of water, water molecules stick to each other very well

23. Check Your Understanding
In this property of water, water molecules stick to each other very well
Answer: COHESION

24. Check Your Understanding
In this property of water, capillary action helps transport water up the roots of plants and trees

25. Check Your Understanding
In this property of water, capillary action helps transport water up the roots of plants and trees
Answer: ADHESION + COHESION

26. Check Your Understanding
In this property of water, ice floats

27. Check Your Understanding
In this property of water, ice floats
ANSWER: Water is less dense as a solid (ice)

28. Check Your Understanding
In this property of water, it takes water a long time to heat up or cool down

29. Check Your Understanding
In this property of water, it takes water a long time to heat up or cool down
ANSWER: High specific heat

30. Check Your Understanding
In this property of water, hydrogen bonds are broken down, and 1 g of water requires 540 calories of heat to turn from a liquid to a gas
ANSWER: High heat of vaporization

31. Carbon

32. Introduction to Carbon
Carbon is the basic building block for all forms of life on Earth.
Fortunately, carbon is also one of the most abundant elements on our planet.
It is the fourth most abundant element in the universe and it is the second most abundant element in the human body.
Oxygen is the most abundant element in the human body.
Like all matter, carbon can neither be created nor destroyed, and so all living organisms must find a way to continually reuse the finite carbon supply that is available.

33. Why study Carbon? All of life is built on carbon Cells ~72% H2O
~25% carbon compounds
carbohydrates
lipids
proteins
nucleic acids
~3% salts
Na, Cl, K…
Why do we study carbon -- is it the most abundant element in living organisms?
H & O most abundant
C is the next most abundant

34. Chemistry of Life Organic chemistry is the study of carbon compounds
C atoms are versatile building blocks
bonding properties
4 stable covalent bonds
Carbon chemistry = organic chemistry
Why is it a foundational atom?
What makes it so important?
Can’t be a good building block if you only form 1 or 2 bonds. H C H H H

35. Carbon and Macromolecules!
Important thing about carbon is that it can bond with many other elements to form SUPER LONG CHAINS of molecules called
MACROMOLECULES!

36. Macromolecules
Smaller organic molecules join together to form larger molecules
macromolecules
4 major classes of macromolecules:
carbohydrates
lipids
proteins
nucleic acids

37. Polymers
Long molecules built by linking repeating building blocks in a chain
monomers
building blocks
repeated small units
covalent bonds
H2O HO H
• great variety of polymers can be built from a small set of monomers
• monomers can be connected in many combinations like the 26 letters in the alphabet can be used to create a great diversity of words
• each cell has millions of different macromolecules
Dehydration synthesis

38. How to build a polymer Synthesis joins monomers by “taking” H2O out
one monomer donates OH–
other monomer donates H+
together these form H2O
requires energy & enzymes
H2O HO H
enzyme
Dehydration synthesis
Condensation reaction

39. How to break down a polymer
Digestion
use H2O to breakdown polymers
reverse of dehydration synthesis
cleave off one monomer at a time
H2O is split into H+ and OH–
H+ & OH– attach to ends
requires enzymes
releases energy
H2O HO H
enzyme
Most macromolecules are polymers
• build:
condensation (dehydration) reaction
• breakdown:
hydrolysis
An immense variety of polymers can be built from a small set of monomers
Hydrolysis
Digestion

40. Check your understanding
Why is carbon so essential to life?

41. Check your understanding
Why is carbon so essential to life?
ANSWER: Because it is the basic building block of life

42. Check your understanding
What property of carbon allows it to form macromolecules?

43. Check your understanding
What is property of carbon allows it to form macromolecules?
ANSWER: It forms four stable covalent bonds

44. Check your understanding
This term refers to long molecules made of up of monomers

45. Check your understanding
This term refers to long molecules made of up of monomers
ANSWER: Polymers

46. Check your understanding
Process by which a polymer is formed from monomers

47. Check your understanding
Process by which a polymer is formed from monomers
ANSWER: Dehydration synthesis a.k.a. condensation reaction

48. Check your understanding
Process by which a polymer is split up into monomers

49. Check your understanding
Process by which a polymer is split up into monomers
ANSWER: Hydrolysis aka Digestion