1. Biology
Energy Transfer Unit

2. What is the Biosphere?
The biosphere is the part of the Earth's surface and atmosphere that contains life.

3. Ecosystems The biosphere is made of ecosystems.
An ecosystem is all of the living and nonliving things in a specific area.

4. Ecosystems Have Two Parts
Abiotic – All of the nonliving things in an ecosystem.
Rocks, water, climate, elevation, ect...

5. Ecosystem Parts Continued
Biotic – All of the living things in an ecosystem.
Plants, animals, fungi, protozoans, algae and bacteria.

6. Community All of the living things in a defined area.
Ex: All forms of life in this room.

7. Population All members of a species found in a defined area.
Ex: All of the opposums in Somerset County

8. Species
A group of organisms that look similar and are able to produce fertile offspring.

9. Habitat
The place where an organism lives.

10. Niche The role an organism plays in its environment.
Organisms can be generalists or specialists.

11. Generalists Species with broad niches.
They can tolerate a wide range of conditions.
Ex: Gray Squirrels

12. Specialists Species with narrow niches.
They have very specific habitat requirements.
Ex: Kirtland's Warbler

13. How do Organisms Deal with Unfavorable Conditions?
Dormancy – Organisms enter a state of reduced activity.
Migration – Organisms move to areas with favorable conditions

14. *Important Fact*
“Energy enters the biosphere via sunlight and chemicals.”
PDE Big Idea 7A

15. Producers or Autotrophs
Organisms that use light or chemicals to produce their own energy.
Use photosynthesis or chemosynthesis

16. Consumers or Heterotrophs
Organisms that must eat in order to gain energy.

17. *Important Fact*
“Animals are important energy consumers obtaining their energy by assembling and recombining fats, carbohydrates and proteins from plants and/or other animals passing through the food web.”
PDE Big Idea 7C

18. Herbivores
Organisms that eat producers.

19. Carnivores
Organisms that eat other consumers.

20. Omnivores
Organisms that eat both producers and consumers.

21. Detritivores Organisms that eat the “garbage” of an ecosystem.
Dead organisms, wastes or fallen leaves

22. Decomposers
Special detritivores that break down dead matter and return nutrients into the ecosystem.
Ex: Bacteria and Fungus

23. *Important Fact*
“Some bacteria and fungi are known as decomposers using dead and decaying organisms as an energy source.”
PDE Big Idea 7D

24. Trophic Levels
An organism’s position in a sequence of energy transfers.

25. Trophic Level Limitations
Only about 10% of the energy available at any one level passes on to the next level.
This limits the number of levels.

26. Food Chain
Food chains trace the transfer of energy through an ecosystem.
They are simple, linear diagrams showing who eats who in an ecosystem.

27. Sample Food Chain

28. Food Web
A complex, branching diagram showing who eats who in an ecosystem.
They show how different food chains are intertwined.

29. Sample Food Web

30. Bioaccumulation
Toxins introduced to an ecosystem accumulate in greater concentrations at the upper trophic levels.

31. *Important Fact* “Food webs consist of intertwined food chains.”
PDE Big Idea 7B

32. *Important Fact*
“As matter and energy flow through the many cycles of food chains, chemical assembly and recombination conserves matter and dissipates energy as heat.”
PDE Big Idea 7E

33. Laws of Thermodynamics
Matter and energy are neither created nor destroyed. They simply change form.

34. Photosynthesis H2O + CO2 + Light  C6H12O6 + O2
Light energy is absorbed by special electrons in chlorophyll.
Electrons begin to move through the plant (electrical energy).
The electrons and their energy are put into the glucose molecule (chemical energy). So, tracing the energy transformation…
Light  Electrical  Chemical

35. Chloroplasts
Stroma - the protein rich fluid that fills in the spaces around the grana
Thylakoids – the part of the chloroplast that contains chlorophyll
Grana – stacks of thylakoids

36. The Light Dependent Reactions

37. Light Independent Reactions
AKA the Calvin Cycle
Discovered by Melvin Calvin and others
He discovered how products from the light dependent reactions were used to make glucose

39. Cellular Respiration The production of ATP from glucose.
It can happen one of two ways:
Aerobic Respiration – Uses oxygen to produce ATP (very efficient)
Anaerobic Respiration – Does not use oxygen to produce ATP (very inefficient)

40. Stages of Respiration Aerobic Begins with glycolysis
Second step is called the Krebs Cycle (named for Hans Krebs)
Anaerobic
Begins with glycolysis
Second step is either lactic acid fermentation or alcoholic fermentation

41. Glycolysis
Literally means breaking glucose (glyco=“glucose” in Latin) (lysis=“to break” in Latin)
It is always the first step in respiration

42. Products:
- 2 Pyruvic acids
- 4 ATP’s (gained 2 ATP’s)
- 2 NADH’s

43. Aerobic Cellular Respiration
C6H12O6 + O2  H2O + CO2 + ATP
Also known as the Krebs Cycle
Discovered by Hans Krebs in 1957

44. Products: - 4 NADH’s -1 ATP - 1 FADH2
- BUT there are 2 pyruvic acids … so
- 8 NADH’s
- 2 ATP’s
- 2 FADH2’s

45. Wrapping Up Aerobic Respiration
The products of glycolysis and the Krebs cycle get added together
Glycolysis made 2 ATP’s and 2 NADH’s
Krebs Cycle made 2 ATP’s, 8 NADH’s and 2 FADH2’s
So, the overall products of both processes are 4 ATP’s, 10 NADH’s and 2 FADH2’s

46. Finally!
After the Krebs Cycle, NADH and FADH2 enter and electron transport chain, undergo chemical reactions and get converted into ATP
Each NADH will make 3 ATP
Each FADH2 will make 2 ATP

47. Total ATP Products ATP’s Made 4 ATP 10 NADH 2 FADH2 4 ATP 30 ATP

49. Anaerobic Respiration
Makes no additional ATP
It just regenerates more NAD+ for glycolysis

50. Lactic Acid Fermentation

51. Alcoholic Fermentation

52. Locations Photosynthesis takes place in the chloroplasts
Light Dependent Reactions – thylakoids
Light Independent – stroma
Glycolysis – cytoplasm
Krebs Cycle – mitochondria
Fermentation – cytoplasm