1. Chemistry Topics for Us
Plant + animal chemical defenses
Atomic structures: Protons, Neutrons, Electrons
Special properties of water
pH: acids + bases
Light + Energy
Organic Chemistry: Carbohydrates, Proteins, Lipids + Nucleic Acids

2. Milkweed contains cardiac glycosides that are poisonous to humans and livestock, as well as alkaloids. 
The glycoside in milkweed is also a chemical defense for monarch butterflies. Caterpillars eat the milkweed plant and store the poisons and make the caterpillar's flesh distasteful to most predators. 

3. Captive bluejays fed monarchs with cardenolides throw up after eating the monarchs.

4. Plants containing cardiac steroids have been used as poisons and heart drugs at least since 1500 B.C. 

5. Periodic Table of the Elements
This chart above is the periodic table of the elements. It depicts the 92 elements that exist in nature and another 21 that can be created artificially. Each element has distinct chemical characteristics. These elements represent a huge variety of potential chemical reactions that can take place.
Elements that are required by living organisms cover just about all potential types of chemical reactions that occur and range across the periodic table. Interesting enough, the elements helium, neon, argon, krypton and so on aren't generally part of living systems because they are stable elements that don't participate readily in chemical reactions. Life itself is base on dynamic chemical reactions. Stable is dead.

6. ELEMENT = Its all about the Protons!
= a substance that can’t be chemically changed into another substance
H=hydrogen, C= carbon, O=oxygen, Au=gold
ELEMENT = # of Protons in an atom
H = 1, He = 2, C = 6, O = 8, Au = 79
ELEMENT = Atomic # = # of Protons
So, if you: Change # Protons in an atom you Change the Element !

7. An atom has protons and neutrons located in a central nucleus
The nucleus is surrounded by electrons, which orbit so fast they form “clouds” around the nucleus 2
Protons
Nucleus 2
Neutrons 2
Electrons
Figure 2.4A
A. Helium atom

8. Common Elements in Organic Molecules

9. SODIUM
ATOM
11 p+
11 e-
electron transfer
CHLORINE
17 p+
17 e-
SODIUM
ION
11 p+
10 e-
CHLORINE
17 p+
18 e-

10. The Amazing Water Molecule
Life began in water
All living things depend on water
Water is a simple molecule, but without it,
Earth may not be inhabitable …but why?

11. Atoms sharing electrons
Water Molecule =
Atoms sharing electrons

12. Electrons drawn to this side
In a water molecule, oxygen’s 8P has a stronger pull on the shared electrons than hydrogen’s 1P
So, the oxygen end of the molecule slightly negatively charged
The hydrogen end of the molecule is slightly positively charged
Water becomes a “POLAR” molecule
Electrons drawn to this side
(–)
(–)
8 protons O H H
1 proton
1 proton
(+)
(+)
Figure 2.9

13. Water’s polarity leads to hydrogen bonding and unusual properties\
water molecules are attracted to the oppositely charged regions on nearby molecules
This attraction forms weak bonds called hydrogen bonds

14. H-bonds =Water is a versatile solvent
Reason why things dissolve in water
Note: only polar molecules dissolve in water
What substances don’t dissolve in water?

15. Evaporation “pulls” water into the roots molecule by molecule
TRANSPIRATION IN PLANTS
Evaporation “pulls” water into the roots molecule by molecule
Adhesion + cohesion
Molecule by molecule water enters the roots

16. Water and it’s Hydrogen Bonds
Xylem cells allow plants to draw water from soil without energy (adhesion + cohesion)
Xylem Plant Vascular Cells

17. High Specific Heat
Reason why rivers, lakes and oceans stay relatively cool
it takes a lot of energy to warm up water
energy is absorbed by hydrogen bonds
This, in turn, keeps our planet from overheating quickly.

18. Evaporative Cooling Reason why sweating cools you off so effectively –
High heat of vaporization (takes lots of energy to evaporate water)

19. Ice is less dense water
So, ice floats and so fish can survive winter under lake ice.

20. Water: A Unique Compound
% of the weight of living organisms
liquid where all of life's chemical reactions occur
Good electrical conductor
Highest surface tension of any common, natural liquid = adhesion + cohesion properties
Expands when it crystallizes, unlike most substances (ice has greater volume than water)
High specific heat (water holds a lot of heat energy)
High heat of vaporization (takes lots of energy to evaporate water)
Water is an extremely important and unique compound, making up about 70 percent of the weight of living organisms. Most of the chemical reactions important to life take place in water, and this is true in living as well as non-living systems.
Water, particularly water that contains dissolved substances, is a good electrical conductor. Water has a very, very high surface tension, which allows many organisms to float on it. Water remains liquid over a wide rage of temperatures, can exist as a solid in the form of ice, and as a gas in the form of water vapor.
Unlike most substances, water expands when it crystallizes and has its maximum density as a liquid just above its freezing point of 0 degrees Centigrade. Because ice is less dense than liquid water, ice doesn't sink to the bottom of lakes and rivers.
Water has a high heat of vaporization and a high specific heat and so greatly modifies environments that have lots of water. For instance, Seattle would be a much colder place in the winter and hotter in the summer if there was no Lake Washington and Puget Sound to moderate daily temperatures.

21. Acids and Bases
Acids are compounds that readily release hydrogen ions (H+) in water.
Bases are substances that readily take up hydrogen ions (H+) and release hydroxide ions (OH-) in solution.
pH scale = Strength measured by concentration of H+ (protons) in water
0-14 scale
The pH of the environment has a profound effect on the chemical reactivity of substances and the character of life itself.

22. The pH Scale

23. The chemistry of life is sensitive to acidic and basic conditions
A compound that releases H+ ions in solution is an acid, and one that accepts H+ ions in solution is a base
Acidity is measured on the pH scale:
0-7 is acidic
8-14 is basic
Pure water and solutions that are neither basic nor acidic are neutral, with a pH of 7

24. Ocean pH + CO2 As carbon dioxide levels go up, pH levels go down.
Acidity depends on the presence of hydrogen ions (the H in pH) and more hydrogen ions mean, a lower pH.
Expose oceans to more CO2 it will produce carbonic acid, lowering pH on a planetary scale. 

25. Acid Rain
When water vapor in the atmosphere mixes with acidic air borne particles (NO2 or SO2) it can kill leaves, trees, fish, etc.
H2O + SO2  H2SO (sulfuric acid)
H2O + NOx  H2NOx (nitric acid)

26. The Electromagnetic Spectrum
The wavelengths of visible
light drive photosynthesis.
We have mentioned that light radiation from the sun is the source of energy for most of life. The part of t he electromagnetic spectrum that includes light encompasses a wide range of frequencies, and what we can actually see as visible light is a very narrow band within that range. Photosynthesis of plants is driven by the narrow range of visible light, ranging from about micrometers.
Other wavelengths can have effects on the environment; for instance, x-rays and gamma rays can be deadly, ultraviolet radiation gives us a sun tan, and also, potentially, skin cancer. Infrared energy heats us, and we use microwaves and radio waves to transmit energy. I'm particularly fond of using microwave energy to heat my lunch.

27. Photosynthesis= CO2 + H20 C6H12O6 + H2O
Light energy from the sun is relatively diffuse, and the process of photosynthesis converts it into more concentrated chemical energy that organisms can use. You likely heard about photosynthesis way back in elementary school. However, in case you weren't listening, we'll review how photosynthesis works.
Using light energy from the sun, plants convert carbon dioxide, nutrients, and water into complex carbohydrate molecules that can be used by many different types of organisms, including humans. Another way of describing photosynthesis is to say that the process "fixes,” or captures, the light energy of the sun into carbohydrate molecules.
Consider that the energy in a glass of milk we might drink for lunch originally came from the sun's light energy, and through photosynthesis, was "fixed” by grass. The grass was eaten by a cow, and the cow used the energy for a variety of chemical reaction, including making milk. The human drinking the milk uses the energy for a variety of chemical reactions. If you were a plant, you could lie out in the sun and make your food, but since you're not, you depend on plants directly or indirectly—by eating animals--for your food. Plants ultimately depend on the sun.
Earlier, I mentioned that some systems, like communities in deep ocean trenches and algae in the very hot Morning Glory pool in Yellowstone Park, utilize energy directly from chemicals from the earth, not the sun.