1. Bell Ringer
What is the difference between potential and kinetic energy?

2. Standard: Communities CLE3255. 3
Standard: Communities CLE Apply the first and second laws of thermodynamics to explain the flow of energy through a food chain or web.
Objectives:
Briefly review the basic chemistry of life.
Distinguish among the types of energy.
Apply the laws of thermodynamics in regards to energy flow in a food chain/web and the “Rule of 10.”

3. From Chemistry to Energy to Life
Chapter 4
From Chemistry to Energy to Life

4. Vocabulary Energy Autotrophs Potential energy Primary producers
Kinetic energy
Photosynthesis
Chemical energy
Cellular Respiration
First law of Thermodynamics
Heterotrophs
Geothermal Energy
Second law of Thermodynamics
Chemosynthesis

5. Macromolecules are Building Blocks of Life
4 Types of Macromolecules
Proteins
Nucleic Acids
Carbohydrates
Lipids

6. Proteins Made of long chains of amino acids What do proteins do?
Provide Structure
Transport Substances
Anitbodies (defend against invaders)
Carry Messages
Act as Enzymes (promote chemical reactions)

7. Nucleic Acids
Carry hereditary (genetic) information and direct the production of proteins.
Two Types
Deoxyribonucleic acid (DNA) contains the hereditary information.
Ribonucleic acid (RNA) directs the building of proteins.

8. Carbohydrates
Organic compounds consisting of carbon, hydrogen, and oxygen.
Used for energy
Build structures such as leaves, lobster shells, and fingernails.

9. Lipids Include Fats Waxes Steroids Do not dissolve in water
Used for energy storage, membranes, and hormones.

10. Cells Cells - the most basic units of organization.
Biologists classify organisms into two groups based on cell structure
Eukaryotic - cells with organelles (internal structures that perform specific functions), including a nucleus
Prokaryotic - single-celled and lack organelles and a nucleus

11. Energy Fundamentals
What can energy do to matter?
Change position
Change physical composition
Change temperature

12. Fundamental Types of Energy
Potential Energy
Energy of position
Examples: rock on a cliff, book on a shelf
Kinetic Energy
Energy of motion
Examples: rock falling off of a cliff, book falling off of a shelf

13. What is chemical energy?
Special type of potential energy that is held in the bonds between atoms.
What are some other examples of potential and kinetic energy?

14. First Law of Thermodynamics
Physical law stating that energy can change from one form to another but cannot be created or lost. The total energy in the universe remains constant and is said to be conserved.

15. Second Law of Thermodynamics
Physical law stating that the nature of energy tends to change from a more ordered state to a less ordered state. Entropy increases.
Entropy – the degree of disorder in a substance, system, or process

16. Energy Conversion Efficiency
The degree to which we successfully capture energy
The ECE is the ratio of useful output of energy to the amount that needs to be input.
Gasoline – 16% of energy is used to power automobile, rest is converted to heat
“Regular” or Incandescent Light Bulbs – 5% of energy

17. Energy Conversion Examples
Gasoline – 16% of energy is used to power automobile, rest is converted to heat
“Regular” or Incandescent Light Bulbs – 5% of energy is converted to light we use, rest escapes as heat
15% efficiency of current solar energy technology

18. Electrolysis of water 50%-70%
Electric motors 30-60%
Household refrigerators low end systems ~ 20%; high end systems ~ 40-50%
Fluorescent lamps 28%
Electric shower 90-95% (Overall it would be more efficient to use a heat pump, requiring less electric energy)
Electric heaters around 95% (all energy is always converted into heat anyway) *

19. How efficient are food chains?
Assignment: Review Energy Pyramid Handouts
Use handouts to help you answer the Energy Pyramid Worksheet (worth 10 points)

20. Light Energy
The sun supplies energy to those organisms that are able to use it to produce their own food; autotrophs, or primary producers.
Autotrophs turn light energy from the sun into chemical energy in a process called photosynthesis.

21. Photosynthesis
Sunlight powers a series of chemical reactions that convert water and carbon dioxide into sugars and oxygen, providing energy that the organism can use.
Provides food for plants/animals.
The equation:
Energy + 6CO2 + 6H2O  C6H12O6 + 6O2

22. Cellular Respiration
The chemical energy created by photosynthesis is used by organisms in the process of cellular respiration.
Releases chemical energy
This extraction of energy occurs in both autotrophs and heterotrophs, or consumers.

23. Cellular Respiration (contd.)
Cells use the reactivity of oxygen to convert glucose back into water and carbon dioxide, and release energy to perform tasks within cells.
The equation:
C6H12O6 + 6O2  6CO2 + 6H2O + Energy
(notice it is opposite of photosynthesis)

24. Geothermal Energy Another major source of energy besides light
Radiation from radioactive elements deep in the Earth heats the interior of the planet
Causes volcanoes, hot water geysers, and produces geothermal energy

25. Hydrothermal Vents Utilize chemical energy instead of light energy
Hydrothermal vents are areas in the deep ocean from which jets of geothermally heated water emerge.
Communities at the vents depend on bacteria at the base of the food web. These bacteria fuel themselves by chemosynthesis, producing sugars.

26. Chemosynthesis
Process by which bacteria use hydrogen sulfide (H2S) to transform inorganic carbon into organic compounds
Like photosynthesis because:
uses H2O and CO2 to produce sugar
energy in sugar is released during cellular respiration

27. Bell Ringer
Why are photosynthesis and cellular respiration dependent on one another?

28. Standard: Embedded Inquiry
CLE3255.Inq.6 Communicate and defend scientific findings.
Objective: Evaluate major hypotheses for the origin of life on Earth.

29. The Origin of Life Early Earth: Formed 4.5 billion years ago
Millions of years, Earth bombarded (hit) by stray material in solar system
Volcanic and tectonic activity was severe
Ultraviolet radiation was intense
Atmosphere – lacked oxygen
Mostly CO2, carbon monoxide (CO), hydrogen, ammonia, methane, H2O vapor

30. Proposed Hypotheses: Primordial Soup
The heterotrophic hypothesis
Life evolved from a soup of simple inorganic chemicals—carbon dioxide, oxygen, and nitrogen—dissolved in the ocean.
Termed heterotrophic because first life forms used organic compounds as energy source.
Scientists have modified their ideas about early atmospheric conditions, seems less likely to represent what actually happened.

31. Proposed Hypotheses: Seeds from Space
Idea that bacteria from space crashed to Earth on meteorites and started life here.
The Murchison meteorite, which fell in Australia in 1969, contained many amino acids which survived impact.
Comets have brought large amounts of water, possibly organic compounds, to Earth.
Hypothesis is becoming more plausible (believable) with continued research.

32. Proposed Hypotheses: Life from Depths
The chemoautotroph hypothesis
Idea that early life was formed in deep-sea vents where sulfur was abundant.
Chemoautotrophs - base of food chain, using chemosynthesis
Some of the most ancient ancestors of today’s life forms likely lived in extremely hot and wet environments.

33. The Fossil Record Earliest evidence of life comes from
3.5-billion-year-old rocks.
Regardless of how it started, life diversified into countless forms over Earth’s long
Fossils are imprints of dead organisms in stone; provide information about plants and animals in different time periods.

34. The Fossil Record (cumulative set of fossils worldwide)
The species living today are a fraction of all the species that have ever lived.
The number of species existing at any one time has increased through history.
There have been several episodes of mass extinction, or simultaneous loss of great numbers of species.

35. The Fossil Record
Many organisms present early in history were smaller and simpler than modern organisms.
Present-day organisms and their genes also help us decipher life’s history.