Science Warm-up 9/6/2011

1. Science Warm-up 9/6/2011 • What are some ways that you get energy? Is this the same for everyone? What about everything around the world? • Write a paragraph response to this prompt. (minimum of 5 sentences)

2. Chapter 8: Cellular Energy Biology B Mr. Wood

3. Section 1: How Organisms Obtain Energy • Thermodynamics • AutotrophsvsHeterotrophs • Metabolism • ATP

4. What is energy? (p.218) • Energy is the ability to do work. • Thermodynamics is the study of the flow and transformation of energy in the universe.

5. The Laws of Thermodynamics • There are 2 main laws: • 1) Energy can be transformed, but energy cannot be created or destroyed. • 2) Energy cannot be converted without the loss of usable energy.

6. Examples: • Recharging a cell phone battery • Buying a new car

7. How do organisms get energy? (p.219) • 2 different varieties: • Auto-trophs • Hetero-trophs • Self-eater • Other-eater • Both are based on the Sun

8. Autotroph Heterotroph Other eater • Self Eater

9. Metabolism (p.220) • Metabolism is all of the chemical reactions in a cell. • Catabolic vs. Anabolic • Breaking down vs Building up

10. The Metabolism of Ecosystems • There is a cycle of energy in an ecosystem.

11. ATP: The Unit of Cellular Energy • Adenosine triphosphate is the cell’s currency for energy • ATP stores energy, and then releases energy when it is turned into ADP

13. Section 2: Photosynthesis • Overview • Phase 1: Light Reactions • Phase 2: Dark Reactions

14. Overview of Photosynthesis (p.222) • Photosynthesis is turning light energy into chemical energy. • Turns sunlight into sugar

15. Phase One: Light Reactions (p.223) • The first step is to absorb light energy • This process happens in the pigments of the chloroplasts.

16. Where photosynthesis starts • Why are chloroplasts green?

17. Phase Two: The Calvin Cycle • This is where energy for the plant is stored for the long term. • Most plants store energy in the form of glucose.

19. Review of photosynthesis • Sunlight splits a water molecule. • Hydrogen ion is passed through an electron transport. • The CO2 moves through the Calvin Cycle. • Excess energy is stored in glucose.

21. Alternative Pathways • C4 Pathway • CAM Plants • Commonly found in desert plants. This is more efficient in very high temperatures, drought and CO2 limitations.

22. Section 3: Cellular Respiration • Organisms obtain energy in a process called cellular respiration. • The equation for cellular respiration is the opposite of the equation for photosynthesis.

23. Phases of Cellular Respiration • There are 2 main phases of cellular respiration: • Glycolysis • Aerobic respiration

24. Glycolysis • Glucose is broken down in the cytoplasm through the process of glycolysis. • Two molecules of ATP and two molecules of NADH are formed for each molecule of glucose (2 total) that is broken down.

25. Glycolysis results in a net gain of 2 ATP molecules. • Most of the energy from the glucose is still contained in the pyruvate. • The series of reactions in which pyruvate is broken down into carbon dioxide is called the Krebs cycle.

27. Electron Transport • The final step for the glucose molecule. • Point at which ATP is produced • Produces 34 ATP

29. Aerobic vs Anaerobic • Aerobic- with oxygen • Long distance running • Marathon • Anaerobic- without oxygen • Sprinting • 100 meter dash

30. Anaerobic respiration • After glycolysis, one of the following 2 processes occurs: • Alcohol fermentation • Wine • Lactic acid fermentation • Muscles