1. KEY CONCEPT All cells need chemical energy.

2. Starch molecule Glucose molecule The chemical energy used for most cell processes is carried by ATP. Molecules in food store chemical energy in their bonds.

6. about 146 ATP from a triglyceride

7. Proteins are least likely to be broken down to make ATP.

8. amino acids not usually needed for energy

10. KEY CONCEPTThe overall process of photosynthesis produces sugars that store chemical energy.

11. Photosynthetic organisms are producers. Producers make their own source of chemical energy. Plants use photosynthesis and are producers. Photosynthesis captures energy from sunlight to make sugars.

14. water and sunlight are needed

15. chlorophyll absorbs energy

16. energy is transferred along thylakoid membrane then to light-independent reactions

18. needs carbon dioxide from atmosphere

20. KEY CONCEPT Photosynthesis requires a series of chemical reactions.

21. The first stage of photosynthesis captures and transfers energy. The light-dependent reactions include groups of molecules called photosystems.

23. energized electrons enter electron transport chain

24. water molecules are split

25. oxygen is released as waste

27. energized electrons are used to make NADPH

31. energy is added and carbon molecules are rearranged

33. mitochondrion animal cell Cellular respiration makes ATP by breaking down sugars. Cellular respiration is aerobic, or requires oxygen. Aerobic stages take place in mitochondria.

35. takes place in cytoplasm

36. splits glucose into two three-carbon molecules

38. releases carbon dioxide

40. takes place in inner membrane

41. energy transferred to electron transport chain

42. oxygen enters process

43. ATP produced

47. The Krebs cycle produces energy-carrying molecules.

49. citric acid(six-carbon molecule)is formed

50. citric acid is broken down,carbon dioxide is released,and NADH is made

51. five-carbon molecule is broken down, carbon dioxide is released, NADH and ATP are made

54. oxygen picks up electrons and hydrogen ions

58. Lactic acid fermentation occurs in muscle cells.

59. glycolysis splits glucose into two pyruvate molecules

60. pyruvate and NADH enter fermentation

61. energy from NADH converts pyruvate into lactic acid

63. NADH is changed back into NAD+

65. cheese

66. bread