Cellular Energy

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

3. Cellular Energy Section 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.

4. Cellular Energy Section 1 How Organisms Obtain Energy Laws of Thermodynamics • First law—energy can be converted from one form to another, but it cannot be created nor destroyed. • Second law—energy cannot be converted without the loss of usable energy.

5. Cellular Energy Section 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.

6. Cellular Energy Section 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 • Cellularrespiration—organic molecules are broken down to release energy for use by the cell

7. Cellular Energy Section 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. ATP

8. Cellular Energy Section 2 Photosynthesis Overview of Photosynthesis • Photosynthesis occurs in two phases. • Light-dependent reactions • Light-independent reactions

9. Cellular Energy Section 2 Photosynthesis Phase One: Light Reactions • The absorption of light is the first step in photosynthesis. • Chloroplasts capture light energy.

10. Cellular Energy Section 2 Photosynthesis Electron Transport • Light energy excites electrons in photosystem II and also causes a water molecule to split, releasing an electron into the electron transport system, H+ into the thylakoid space, and O2 as a waste product.

11. Cellular Energy Section 2 Photosynthesis • The excited electrons move from photosystem II to an electron-acceptor molecule in the thylakoid membrane. • The electron-acceptor molecule transfers the electrons along a series of electron-carriers to photosystem I.

12. Cellular Energy Section 2 Photosynthesis • Photosystem I transfers the electrons to a protein called ferrodoxin. • Ferrodoxin transfers the electrons to the electron carrier NADP+, forming the energy-storing molecule NADPH.

13. Cellular Energy Section 2

14. Cellular Energy Section 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.

15. Cellular Energy Section 2

16. Cellular Energy Section 2 Photosynthesis • Six CO2 molecules combine with six 5-carbon compounds to form twelve 3-carbon molecules called 3-PGA. • The chemical energy stored in ATP and NADPH is transferred to the 3-PGA molecules to form high-energy molecules called G3P.

17. Cellular Energy Section 2 Photosynthesis • Two G3P molecules leave the cycle to be used for the production of glucose and other organic compounds. • An enzyme called rubisco converts the remaining ten G3P molecules into 5-carbon molecules called RuBP. • These molecules combine with new carbon dioxide molecules to continue the cycle.

18. Cellular Energy Section 2 Photosynthesis Alternative Pathways • C4 plants • CAM plants

19. Cellular Energy Section 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.

20. Cellular Energy Section 3 Cellular Respiration • Cellular respiration occurs in two main parts. • Glycolysis • Aerobic respiration

21. Cellular Energy Section 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.

22. Cellular Energy Section 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.

23. Cellular Energy Section 3 Cellular Respiration • The net yield from the Krebs cycle is six CO2 molecules, two ATP, eight NADH, and two FADH2.

24. Cellular Energy Section 3

25. Cellular Energy Section 3 Cellular Respiration Electron Transport • Final step in the breakdown of glucose • Point at which ATP is produced • Produces 24 ATP

26. Cellular Energy Section 3 Cellular Respiration Anaerobic Respiration • The anaerobic pathway that follows glycolysis • Two main types • Lactic acid fermentation • Alcohol fermentation Cellular Respiration

27. Cellular Energy Chapter Chapter Resource Menu Chapter Diagnostic Questions Formative Test Questions Chapter Assessment Questions Standardized Test Practice connected.mcgraw-hill.com Glencoe Biology Transparencies Image Bank Vocabulary Animation Click on a hyperlink to view the corresponding feature.

28. A B C D Cellular Energy Chapter CDQ 1 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.

29. A B C D Cellular Energy Chapter CDQ 2 Chapter Diagnostic Questions In which metabolic process are molecules broken down to produce carbon dioxide and water? photosynthesis cellular respiration homeostasis fermentation

30. A B C D Cellular Energy Chapter CDQ 3 Chapter Diagnostic Questions At the end of the Calvin cycle, where is energy stored? NADPH ATP chloroplast glucose

31. A B Cellular Energy Chapter FQ 1 Section 1 Formative Questions Which law of thermodynamics explains why the ladybug receives the least amount of usable energy? the first law of thermodynamics the second law of thermodynamics

32. A B Cellular Energy Chapter FQ 2 Section 1Formative Questions All of the energy from the food you eat comes from the sun. true false

33. A B C D Cellular Energy Chapter FQ 3 Section 1 Formative Questions Why is cellular respiration a catabolic pathway? Energy is used to form glucose and oxygen. Energy is converted from water to carbon dioxide. Energy that is lost is converted to thermal energy. Energy is released by the breakdown of molecules.

34. A B C D Cellular Energy Chapter FQ 4 Section 1 Formative Questions Why is adenosine triphosphate (ATP) such an important biological molecule? It captures light energy from the sun. It is produced in anabolic pathways. It stores and releases chemical energy. It converts mechanical energy to thermal energy.

35. A B C D Cellular Energy Chapter FQ 5 Section 2 Formative Questions Where in the plant cell does photosynthesis take place? chloroplasts Golgi apparatus mitochondria vacuoles

36. A B C Cellular Energy Chapter FQ 6 Section 2 Formative Questions Which range of wavelengths is reflected by chlorophylls a and b? 400-500 nm 500-600 nm 600-700 nm

37. A B C D Cellular Energy Chapter FQ 7 Section 2 Formative Questions Which mechanism of photosynthesis uses the movement of hydrogen ions (H+) across a concentration gradient to synthesize ATP? absorption chemiosmosis electron transport C2 pathway

38. A B C D Cellular Energy Chapter FQ 8 Section 2 Formative Questions How are the C4 pathway and the CAM pathway an adaptive strategy for some plants? They accelerate photosynthesis. They release more oxygen. They help the plant conserve water. They reduce the requirement for ATP.

39. A B C D Cellular Energy Chapter FQ 9 Section 3 Formative Questions What is the overall purpose of cellular respiration? to make ATP to process H2O to store glucose to deliver oxygen

40. A B C D Cellular Energy Chapter FQ 10 Section 3 Formative Questions Which represents the general sequence of cellular respiration? TCA cycle  chemiosmosis  glycolysis glycolysis  Krebs cycle  electron transport electron absorption  catalysis  phosphorylation aerobic pathway  anaerobic pathway  fermentation

41. A B C Cellular Energy Chapter FQ 11 Section 3 Formative Questions Which stage of cellular respiration is the anaerobic process? glycolysis Krebs cycle electron transport

42. A B C D Cellular Energy Chapter FQ 12 Section 3Formative Questions Which molecule generated by the Krebs cycle is a waste product? CoA CO2 FADH2 NADH

43. A B C D Cellular Energy Chapter CAQ 1 Chapter Assessment Questions Look at the following figure. Which part of the chloroplast is a sac-like membrane arranged in stacks? grana stroma thylakoids Golgi apparatus

44. A B C D Cellular Energy Chapter CAQ 2 Chapter Assessment Questions During the Krebs cycle, pyruvate is broken down into what compound? H2O O2 CO CO2

45. A B C D Cellular Energy Chapter CAQ 3 Chapter Assessment Questions Look at the following figure. Which molecule is released when ATP becomes ADP? phosphate group water molecule ribose sugar energy cells

46. A B Cellular Energy A B Chapter STP 1 Standardized Test Practice Which metabolic process is photosynthesis?

47. A B C D Cellular Energy Chapter STP 2 Standardized Test Practice At the beginning of photosynthesis, which molecule is split to produce oxygen (O2) as a waste product? CO2 H2O C6H12O6 3-PGA

48. A B C D Cellular Energy Chapter STP 3 Standardized Test Practice Which molecule helps provide the energy that drives this cycle? 3-PGA CO2 NADPH rubisco

49. A B C D Cellular Energy Chapter STP 4 Standardized Test Practice Which product of the Calvin cycle is used for the production of glucose and other organic compounds? ADP CO2 G3P NADP+

50. A B C D Cellular Energy Chapter STP 5 Standardized Test Practice What is the final step of cellular respiration? O2 and H+ form H2O. Electrons and H2O generate ATP. C6H12O6 is broken down into CO2. NADH and FADH2 gain electrons.