1. Biochemistry – the study of the
compounds and processes
occurring in living things

5. Protons – Positive Charge (+) Neutrons – Neutral Charge
Distribution of Subatomic Particles:
Protons – Positive Charge (+)
Neutrons – Neutral Charge
Electrons – Negative Charge (-)
*Both protons and neutrons are
located in the nucleus of the atom
*Electrons are located in energy
levels or shells around the nucleus

6. Two Simplified Models of a Helium (He) Atom
This model was first proposed by
Niels Bohr.

7. Animations on Atoms and
Chemical Bonds
Bozeman Science: Atoms and the Periodic Table

8. First Level: 2 electrons maximum Second Level: 8 electrons maximum
Electron Distribution in Energy Levels:
First Level: 2 electrons maximum
Second Level: 8 electrons maximum
Third Level: 18 electrons maximum

9. Electron Configurations of
the First 18 Elements

10. TED Talk: Just How Small is an Atom?

11. Isotopes: Atoms of the same
element with the same number
of protons but different numbers
of neutrons
Examples: Carbon 13 (7 neutrons),
Carbon 14 (8 neutrons)

12. What types of bonds are weak?
Bond formation and chemical
reactions involve the
electrons that surround each atom.
What types of bonds are weak?

13. Van der Waals Interactions
occur when transiently positive and negative regions of molecules attract each other

15. What types of bonds are strong?
Ionic
Covalent

16. What sort of covalent bonds are seen here?

17. Electron Transfer and Ionic Bonding

18. A Sodium-Chloride Crystal
This compound
has 2 or more
elements in
definite proportions

19. Ionic and Covalent Bonds:

20. A molecule is the smallest part of a compound.
Water is an example of a polar molecule.

21. Water Cycles between Earth and the Atmosphere
What does it mean to say that water cycles?
Why is solar radiation important in the water cycle?
What processes on Earth involve water moving from one place to another?
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22. Water Cycles between Earth and the Atmosphere
Processes and parts of the water cycle include:
precipitation
interception
infiltration
runoff
groundwater
deep seepage/deep storage
evapotranspiration
evaporation
transpiration

23. Water Cycles between Earth and the Atmosphere
What is a reservoir in the water cycle?
What is a flux in the water cycle?
The Water Cycle:
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24. ** The numbers represent water flow in
billion billion grams per year

25. © 2015 Pearson Education, Inc.
Which of these is the largest reservoir of freshwater on Earth?
the atmosphere
groundwater
lakes
oceans
polar ice caps and glaciers
Answer: E
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26. © 2015 Pearson Education, Inc.
Evaporation from the oceans exceeds precipitation into the oceans. Which of these processes or parts of the water cycle does not contribute water to the oceans?
transpiration by marine algae
melting ice from polar ice caps
groundwater seepage
rivers
All of these processes or parts of the water cycle add water to the oceans.
Answer: A
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27. Polar Covalent Bonds in a Water Molecule

28. Chemical Reaction Between
Hydrogen and Oxygen

29. Hydrogen Bonds Polar covalent
Oxygen is one of the most electronegative elements
In a water molecule electronegative oxygen “hogs” electrons.
This “hogging” of electrons results in which type of bond between oxygen and hydrogen within the water molecule?
Polar covalent

30. Hydrogen bonds occur between two polar molecules, or between different polar regions of one large macro-molecule.
One “relatively” negative region is attracted to a second “relatively” positive region.

31. Why is water necessary for life?
What cellular processes use water?

32. Even musical artists have composed songs based on water:

33. Polar
Covalent
Bond

34. What are the characteristics of water that contribute to earth’s fitness for life?

35. Water Structure:

39. A. Water is Cohesive and Adhesive
Cohesion
Adhesion
Why is it that a person who jumps off a bridge into water, dies?

40. Water Transport in Plants

41. Cohesion also leads to high viscosity of water
Viscosity – force required for an object to move through the liquid
water has a frictional resistance 100 greater than air
What is a common body shape seen in aquatic vertebrates?
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42. © 2015 Pearson Education, Inc.
Many aquatic vertebrates have a streamlined (torpedo) shape
helps to reduce frictional resistance
many examples of convergent evolution in fish, reptiles, birds, and mammals
Figure 3.6 The body of the sperm whale (Physeter catodon) is streamlined in reverse, with a short, rounded front and a rapidly tapering body. This shape meets the least water resistance.
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43. Water has
a great
surface
tension!

44. B. Moderation of Temperature
Why is it beneficial if water has a high specific heat?
Where do we see this characteristic in our lives?
Pacific Ocean
Boiling water

45. C. Water has a High Heat of Vaporization
What does this property of water do?
Moderates the Earth’s climate
Stabilizes the temperature of aquatic ecosystems, which effects the life that lives there.
Allows for evaporative cooling

47. Evaporative
Cooling

48. D. Water Expands as it freezes:
Prevents deep bodies of water from freezing from the bottom up.
As water freezes it releases heat to water below and insulates it.
As water freezes H bonds form releasing heat. As ice melts H bonds break absorbing heat. Both of these factors make seasonal transitions less abrupt!

51. Why ice really does float:

52. The Structure of Ice

53. E. Water is a Versatile Solvent
Polar compounds dissolve in water.
Nonpolar compounds do not dissolve in water.

54. Water As A Solvent:

55. Chemistry of Water: https://www. nsf
Chemistry of Ice: 
Chemistry of Salt: 

56. Light Varies with Depth in Aquatic Environments
When light strikes the surface of the water
some light is reflected and some light is transmitted
The lower the angle at which it strikes the surface, the more light is reflected.
How does this vary during the day and seasonally?
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57. Temperature Varies with Water Depth
Sunlight warms the surface waters
winds and waves mix the surface waters
Distributes heat vertically
decline in water temperature with depth slower than decline in solar radiation
Below mixed layer, temperatures drop rapidly  thermocline
Below thermocline water temperature further declines with depth but at a slower rate
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58. Oxygen Diffuses from the Atmosphere to Surface Waters
How are gases exchanged between water and the atmosphere?
Which two gases are the most important for aquatic organisms?
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59. Diffusion is affected by solubility and the diffusion gradient
Diffusion – movement of molecules from an area of high concentration to an area of low concentration
Diffusion is affected by solubility and the diffusion gradient
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60. Solubility is a function of:
temperature – solubility decreases as temperature increases
pressure – solubility increases as atmospheric pressure increases
salinity – solubility decreases as salinity increases
Diffusion gradient – difference in concentration between the air and water
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61. Oxygen is not distributed evenly in the oceans
Highest levels near the surface (upper 10 to 20 meters)
diffusion and photosynthesis
As depth increases, oxygen concentration decreases
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62. Water Movements Shape Freshwater and Marine Environments
What are the different types of water movement?
How does this affect aquatic environments?
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63. Where would you find estuaries?
The Transition Zone between Freshwater and Saltwater Environments Presents Unique Constraints
What is an estuary?
Where would you find estuaries?
Why is an estuary environment challenging for aquatic organisms?
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64. Estuary – where freshwater and saltwater mix
The Transition Zone between Freshwater and Saltwater Environments Presents Unique Constraints
Estuary – where freshwater and saltwater mix
Temperatures fluctuate daily and seasonally
Salinity varies vertically
saltwater is more dense than freshwater
currents and winds can mix the water
Salinity varies horizontally
the waters with the lowest salinity are at the river mouth
the waters with the highest salinity are at the sea
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65. The Transition Zone between Freshwater and Saltwater Environments Presents Unique Constraints
Organisms living in an estuary have adaptions to these changes in salinity
physiological
bull sharks are able to live in both marine and freshwater environments through adjustments in osmoregulation
behavioral
fish can move to area of suitable salinity
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66. Acidity Has a Widespread Influence on Aquatic Environments
How does pH affect aquatic organisms?
Directly influences physiological processes
most organisms cannot reproduce below pH 4.5
Indirectly influences through heavy metal concentration
acidic waters contain high concentrations of aluminum
The sulfuric acid from acid rain reacts with the aluminum hydroxide in a neutralization reaction.
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67. The pH
Scale of
Some
Aqueous
Solutions