1. ES101 9/21/10 Ecology III Tutor – HIGHLY RECOMMENDED!
Frangelica Odell, M&W, 6-8pm, MH201
reading Qs due Thurs.; forest lab due next Wed.

2. ES101 9/21/10 Ecology III Tutor – HIGHLY RECOMMENDED!
Frangelica Odell, M&W, 6-8pm, MH201
reading Qs due Thurs.; forest lab due next Wed.
Exam 1 is two weeks from today
- Will be a combination of mult. choice and essays.
- We will use some of the clicker questions from the next several lectures (including today!) on the exam.

3. Matter and Energy
Matter = anything that has volume and mass
Energy = ability to do work
Kinetic energy (k.e.) = energy in anything that moves (includes light waves, heat, etc.)
Potential energy (p.e.) = stored energy
Chemical p.e. = energy stored in the bonds of molecules
Gravitational p.e. =
energy stored in something that can fall

4. Laws of Thermodynamics
Thermodynamics = how energy is transferred
First Law: Energy is conserved = can’t create or destroy energy
Can move it around and change forms (kineticchem. p.e., etc.)
Food = Chem. p.e.
Food + oxygen = releases stored energy
Allows motion in body = Kinetic p.e.

5. Laws of Thermodynamics
Second Law: Every time energy is moved or transformed, some energy is released as heat
Heat is a low quality form of energy – hard to use it to do work
Need to do work to keep
order in universe
Entropy (=disorder)
in universe is increasing
Ex: Brick wall; clean room; both need energy to stay organized

6. Second Law Example Car engine Gas is concentrated chem. p.e.
Converted to motion of car
Heat, gases are also released
<20% of gas energy becomes motion – rest is wasted!

7. A little chemistry… Molecule = 2 or more atoms bonded together
Organic molecule = large, complex with lots of carbon
Ex. C6H12O6 glucose
Inorganic molecule = usually smaller, little or no carbon
Ex. NO3= nitrate, NH3 = ammonia,
CO2 = carbon dioxide

8. Energy for life All life needs energy
Producers: Species that capture own energy. Use:
Chemosynthesis: Inorganic chemicals used as energy sources (not very common) OR
Photosynthesis: Sun used as energy source
Consumers: Species that eat other life forms to get energy

9. All of the energy in all of the food you eat ultimately began with
an animal eating a plant
a plant growing somewhere
the sun
fossil fuels

10. Photosynthesis Carbon dioxide + Water + Light energy 
Glucose (stored energy) +
Oxygen +
heat
Biomass = living weight = a measure of energy stored
More plant growth, more biomass
Reverse is respiration – production of useful energy from stored energy:
Glucose (stored energy) +
Oxygen 
Carbon dioxide +
Water +
energy +
heat

11. Conservation of Energy: How is it demonstrated in a Food web?
1st Law of Thermod -
Conservation of Energy:
How is it demonstrated in a Food web?
energy moves around and changes forms, but is not created or destroyed.
Top carnivores
Primary carnivores
Herbivores
Producers
sun

12. 2nd Law of Thermod. – Ecosystem example:
Drawing of energy in plants, herbivores, carnivores; size of box = amt of energy

13. 2nd Law of Thermod. – Ecosystem example: Ecological Pyramid =
most energy (measured as biomass) in ecosystem is in plants; less energy as you go up food chain.
Energy lost to heat and waste, not converted to new biomass

14. Energy lost to heat and waste, not converted to new biomass
Ecological Pyramid =
Energy lost to heat and waste, not converted to new biomass
top predators are rare because need a lot of animals, land area, to support them
Explains why can feed more people on a vegetarian diet than a meat diet –
meat requires more food, energy, land.

15. Explains why can feed more people on a vegetarian diet than a meat diet –
meat requires more food, energy, land.
Takes 16 lbs of plant to make 1 lb of beef

16. Which of the following groups has the most total biomass in an ecosystem?
omnivores
plants
herbivores
carnivores

17. Nutrient cycles Energy flows in one direction – towards disorder
– life requires energy from sun
Nutrients can go in a cycle
Nutrients – elements needed for life
Macronutrients – need A LOT:
Carbon: Backbone of organic molecules; carbohydrates, fats, sugars, etc
Nitrogen: Amino acidsproteins; enzymes; DNA
Phosphorus: DNA; Cell membranes

18. According to the best scientific evidence, which of the following is the main cause of recent changes in the earth’s climate?
sun spots
ocean currents
ozone depletion
the greenhouse effect
all of the above