1. Chapter 8 Cellular Energy

2. Cooperative Activity What do you know about energy?

3. Energy - what we know Ability to do work Cannot be created or destroyed Can change forms

4. Some usable energy is lost ! Energy “lost” is converted to thermal energy ( a.k.a. heat) Therefore, Entrophy (unusable energy) increases! When Energy Changes Forms

5. Stored in chemical bonds Released when bonds are broken Needed to form bonds Energy

6. All living organisms need energy to live Directly or indirectly all the energy for life comes from the SUN! Why do we care about Energy?

7. Autotrophs make their own food by converting: Autotrophs & Heterotrophs

8. Heterotrophs need to ingest food to obtain energy. Autotrophs & Heterotrophs

9. Review: Chemical Reactions Chemically changing substances Metabolism: sum of all the chemical reactions that occur in our body

10. Chemical equations show how substances change Reactants  Products Na + Cl  NaCl Review: Chemical Reactions (cont.)

11. ATP ( Adenosine triphosphate) Portable form of energy “Energy currency” – Delivers energy where needed in cell

12. Adenosine triphosphate is made of: –Adenine –Ribose sugar –3 phosphate groups ATP

13. Photosynthesis

14. How plants convert solar energy into glucose Takes place in chloroplasts

15. Why is it called photosynthesis? Photo means “light” Synthesis means “to put together” What are we putting together? glucose

16. Chloroplasts Capture light; found mostly in leaves Contain pigments like chlorophyll Chlorophyll Chloroplast

18. Chloroplasts & Chlorophyll

19. Chlorophyll = main pigment Each pigment reflects a different color Accessory Pigments

20. Accessory Pigments (cont.) Carotene – Orange Xanthophyll – Yellow Anthocyanin – Red

21. Phases of Photosynthesis 1.Sunlight is converted into ATP (aka light dependent reaction) 2.Calvin Cycle: ATP is converted into glucose (aka light independent or dark reaction)

22. Photosynthesis: Chemical Equation Reactants 6 CO 2 + 6 H 2 O -------------> C 6 H 12 O 6 + 6 O 2 Products Light http://www.biology.ualberta.ca/facilities/multimedia/uploads/alberta/Photo.html

24. What affects the rate of photosynthesis? Light Intensity Temperature Water Other

25. Why do leaves fall off the tree? Chlorophyll breaks down in cold temps No use for leaves so they fall off to save energy Trees hibernate in winter

26. What’s up with that tree? Why are Japanese Maple trees red? – Anthocyanin Do they perform photosynthesis? – Yes

28. Cellular Respiration Process of releasing energy stored in the bonds of glucose http://glencoe.mcgraw-hill.com/sites/dl/free/0078617340/164155/00053412.html

29. Chemical Equation: Reactants  Products C 6 H 12 O 6 + 6 O 2  6 CO 2 + 6 H 2 O + Energy Cellular Respiration

30. Two types: -Aerobic – requires oxygen -Anaerobic – no oxygen is required Cellular Respiration

31. Step 1 – Glycolysis Takes place in cytoplasm Does not require oxygen (Anaerobic)

32. Glyco – refers to glucose Lysis – means to “cut” Step 1 – Glycolysis

33. We break down glucose to provide energy for the cell! Step 1 – Glycolysis

34. During Glycolysis 2 ATP & 2 NADPH (energy- carrier) molecules are produced per glucose molecule. 2 ATP’s needed to start reactions! Step 1 – Glycolysis

35. 4 ATP – 2 ATP = 2 ATP & 2 NADPH (produced) What is the net gain of ATP molecules at the end of glycolysis? ______ Step 1 – Glycolysis

36. After glycolysis the pathway can go ONE of two ways.

37. Pathways: Aerobic cellular respiration OR Fermentation

38. 2. Fermentation (Aerobic) Only 2 ATP produced Occurs during rapid & heavy exercise Feel burning sensation in muscles

39. 2 Types of Fermentation: 1. Alcohol fermentation – occurs in yeast and some bacteria

40. Found in breads and alcoholic beverages! Produces ethyl alcohol Alcohol Fermentation (Aerobic)

41. 2. Lactic acid fermentation – occurs in skeletal muscle and in several microorganisms to produce foods like: cheese, yogurt & sour cream. 2 Types of Fermentation:

42. Produced during periods of strenuous exercise Lactic acid builds up and muscles feel “sore” 2. Lactic Acid Fermentation (Aerobic)

43. 2. Respiration (Aerobic) Takes place in mitochondria Requires oxygen (aerobic) 34 ATP produced

44. and the total is… 4 ATP: Glycolysis & Fermentation 36 ATP: Glycolysis & Respiration

45. Question: Which path do you think is the best for a sprint? Explain

46. Question: Which path do you think is best for a 20 min run? Explain

47. ~ Cellular Respiration ~ The Chemical Equation Reactants C 6 H 12 O 6 + 6 O 2  6 CO 2 + 6 H 2 O + ATP Products

48. Comparing the reactions Photosynthesis 6 CO 2 + 6 H 2 O + Light  C 6 H 12 O 6 + 6 O 2 Cellular Respiration C 6 H 12 O 6 + 6 O 2  6 CO 2 + 6 H 2 O + ATP