Chapter 8 Cellular Energy

2. Chapter 8 Cellular Energy Section 1: How Organisms Obtain Energy Section2: Photosynthesis Section 3: Cellular Respiration

3. BELLRINGER!!! Write the following chemical equations in your science notebook: PHOTOSYNTHESIS carbon dioxide + water → glucose + oxygen CELLULAR RESPIRATION glucose + oxygen → carbon dioxide + water +energy

4. How Organisms Obtain Their Energy(Section 8.1) MAIN IDEA: All living organisms use energy to carry out all biological processes.

5. Objectives: Summarize the two laws of thermodynamics. Compare and Contrast autotrophs and heterotrophs. Describe how ATP works in a cell. How Organisms Obtain Their Energy(Section 8.1)

6. Review Vocabulary trophic level – each step in a food chain or a food web.

7. energy thermodynamics metabolism photosynthesis cellular respiration adenosine triphosphate (ATP) NEW VOCABULARY

8. Cellular Energy Chapter 8 8.1 How Organisms Obtain Energy Transformation of Energy • Energy is the ability to do work. • Thermodynamics is the study of the flow and transformation of energy in the universe.

9. 8.1 How Organisms Obtain Energy Cellular Energy Chapter 8 Laws of Thermodynamics • First law — energy can be converted from one form to another and it cannot be created nor destroyed.

10. 8.1 How Organisms Obtain Energy Cellular Energy Chapter 8 • Second law — energy cannot be converted without the loss of usable energy. • A diagram that can show the relative amounts of energy, biomass, or numbers of organisms at each trophic level. • In a pyramid of energy, approximately 90% of the energy is transformed at each level (10 percent law).

11. Cellular Energy Chapter 8 8.1 How Organisms Obtain Energy Autotrophs and Heterotrophs • Autotrophs are organisms that make their own food. • Heterotrophs are organisms that need to ingest food to obtain energy. • Chemoautotrophs are organisms that use inorganic substances such as hydrogen sulfide as a source of energy.

12. Heterotrophs are dependent on autotrophs. TRUE! Autotrophs depend on heterotrophs for food. FALSE Autotrophs make their own food. TRUE! Heterotrophs make food using light energy. FALSE REMEDIATION(True or False)

13. Cellular Energy Chapter 8 8.1 How Organisms Obtain Energy Metabolism • All of the chemical reactions in a cell • Photosynthesis— light energy from the Sun is converted to chemical energy for use by the cell (anabolic pathway) • Cellular respiration— organic molecules are broken down to release energy for use by the cell (catabolic pathway)

14. Cellular Energy Chapter 8 8.1 How Organisms Obtain Energy ATP: The Unit of Cellular Energy • ATP releases energy when the bond between the second and third phosphate groups is broken, forming a molecule called adenosine diphosphate (ADP) and a free phosphate group.

15. 8.1 Section Summary • The laws of thermodynamics control the flow and transformation of energy in organisms. • Autotrophs produce their own food, whereas heterotrophs obtain energy from the food they digest. • Cells store and release energy through coupled anabolic and catabolic reactions. • The energy released from the breakdown of ATP drives cellular activities.

16. Photosynthesis(Section 8.2) MAIN IDEA: Light energy is trapped and converted into chemical energy during photosynthesis.

17. Objectives: Summarize the two phases of photosynthesis. Explain the function of a chloroplast during the light reactions. Photosynthesis(Section 8.2)

18. carbohydrate – an organic compound containing only carbon, hydrogen, and oxygen, usually in a 1:2:1 ratio. REVIEW VOCABULARY

19. thylakoid granum stroma pigment NADP+ Calvin cycle rubisco NEW VOCABULARY

21. Cellular Energy Chapter 8 8.2 Photosynthesis Overview of Photosynthesis • Photosynthesis occurs in two phases. • Light-dependent reactions • Light-independent reactions

22. Cellular Energy Chapter 8 8.2 Photosynthesis Phase One: Light Reactions • The absorption of light is the • first step in photosynthesis. • Chloroplasts capture light energy.

23. Carotenoids produce the colors of carrots and sweet potatoes. Photosynthesis(Section 8.2)

24. As trees prepare to lose their leaves before winter, the chlorophyll molecules break down, revealing the colors of the pigments. Photosynthesis(Section 8.2)

25. Cellular Energy Chapter 8 8.2 Photosynthesis Phase Two: The Calvin Cycle • In the second phase of photosynthesis, called the Calvin cycle, energy is stored in organic molecules such as glucose.

26. Cellular Energy Chapter 8 8.2 Photosynthesis • An enzyme called rubisco converts inorganic carbon dioxide molecules into organic molecules during the final step of the Calvin cycle.

27. Cellular Energy Chapter 8 8.2 Photosynthesis Alternative Pathways • C4 plants keep their stomata • (plant cell pores) closed during • hot days.

28. Cellular Energy Chapter 8 8.2 Photosynthesis Alternative Pathways • CAM plantspathway occurs in water-conserving plants that live in deserts, salt marshes, and other environments where access to water is limited.

29. 8.2 Section Summary • Plants contain chloroplasts with light- absorbing pigments that convert light energy into chemical energy. • Photosynthesis is a two-phase process that consists of the light reactions and the Calvin cycle. • In the light reactions, autotrophs trap and convert light energy into chemical energy in the form of NADPH and ATP. • In the Calvin cycle, chemical energy in ATP and NADPH is used to synthesize carbohydrates such as glucose.

30. MAIN IDEA:Living organisms obtain energy by breaking down organic molecules during cellular respiration. CELLULAR RESPIRATIONSection 8.3

31. Section 8.3 Objectives • Summarize the stages of cellular respiration. • Compare alcoholic fermentation and lactic acid fermentation.

32. cyanobacterium – a type of eubacterium that is a photosynthetic autotroph. mitochondria – membrane-bound organelles that convert fuel into energy that is available to the rest of the cell (often referred to as the “powerhouses” of cells). Review Vocabulary

33. anaerobic process aerobic respiration aerobic glycolysis Krebs cycle fermentation NEW VOCABULARY

34. Cellular Energy Chapter 8 8.3 Cellular Respiration Overview of Cellular Respiration • Organisms obtain energy in a process called cellular respiration. • The equation for cellular respiration is the opposite of the equation for photosynthesis.

35. Cellular Energy Chapter 8 8.3 Cellular Respiration Review of Photosynthesis and an Overview of Cellular Respiration

36. Cellular Energy Chapter 8 8.3 Cellular Respiration • Cellular respiration occurs in two main parts. • Glycolysis • Aerobic respiration

37. Cellular Energy Chapter 8 8.3 Cellular Respiration 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 that is broken down.

38. Cellular Energy Chapter 8 8.3 Cellular Respiration Krebs Cycle • Glycolysis has a net result of two ATP and two pyruvate. • 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.

39. Cellular Energy Chapter 8 8.3 Cellular Respiration Electron Transport • Final step in the breakdown of glucose • Point at which ATP is produced • Produces 24 ATP

40. Cellular Energy Chapter 8 8.3 Cellular Respiration Anaerobic Respiration • The anaerobic pathway that follows glycolysis • Two main types • Lactic acid fermentation • Alcohol fermentation Cellular Respiration

41. Section 8.3 Summary • Many living organisms use cellular respiration to break down glucose. • The stages of cellular respiration are glycolysis, Krebs cycle, and electron transport. • In the absence of oxygen, cells can sustain glycolysis by fermentation.

43. Cellular Energy Chapter 8 Chapter Resource Menu Chapter Diagnostic Questions Formative Test Questions Chapter Assessment Questions Standardized Test Practice biologygmh.com Glencoe Biology Transparencies Image Bank Vocabulary Animation Click on a hyperlink to view the corresponding lesson.

44. Cellular Energy Chapter 8 Chapter Diagnostic Questions Which statement describes the law of conservation of energy? Energy cannot be converted or destroyed. Energy can be converted and destroyed. Energy can be converted but not destroyed. Energy can be destroyed but not converted.

45. Cellular Energy Chapter 8 Chapter Diagnostic Questions In which metabolic process are molecules broken down to produce carbon dioxide and water? photosynthesis cellular respiration homeostasis fermentation

46. Cellular Energy Chapter 8 Chapter Diagnostic Questions At the end of the Calvin cycle, where is energy stored? NADPH ATP chloroplast glucose

47. Cellular Energy Chapter 8 8.1 Formative Questions Which law of thermodynamics explains why the ladybug receives the least amount of usable energy?

48. Cellular Energy Chapter 8 8.1 Formative Questions the first law of thermodynamics the second law of thermodynamics

49. Cellular Energy Chapter 8 8.1 Formative Questions True or False All of the energy from the food you eat comes from the sun.

50. Cellular Energy Energy is used to form glucose and Energy is converted from water to Energy that is lost is converted to Energy is released by the breakdown oxygen. carbon dioxide. thermal energy. of molecules. Chapter 8 8.1 Formative Questions Why is cellular respiration a catabolic pathway?