Ch. 8 & 9 – Photosynthesis and Cellular Respiration

1. Ch. 8 & 9 – Photosynthesis and Cellular Respiration

2. I. Energy and Life A. All organisms require energy for survival. 1. Ultimately, all of the energy in food comes from the sun.

3. I. Energy and Life 2. Autotrophs – organisms that make their own food using energy from the sun a. Example: Plants, algae, and some bacteria can trap energy from the sun (light energy) and convert it into food (chemical energy)

4. I. Energy and Life 3. Heterotrophs – organisms that eat plants or other animals to get energy b. Example: Animals and other organisms cannot trap sunlight directly for food; instead they eat green plants or animals for food.

5. I. Energy and Life • Why do organisms need energy? To move, breathe, reproduce • Why do cells need energy? Active transport, cell division, to make proteins • Where does energy come from? Food (carbohydrates = quick energy) (lipid= long term energy)

6. I. Energy and Life B. Two Types of Cellular Energy

7. I. Energy and Life 1. ATP (Adenosine Triphosphate) – a molecule with 3 phosphate groups, ribose (a sugar), and adenine (a nitrogen base).

8. I. Energy and Life 2. ADP (Adenosine Diphosphate) – a molecule with 2 phosphate groups, ribose (a sugar), and adenine (a nitrogen base). a. ADP is created when ATP loses energy and a phosphate.

9. I. Energy and Life ATP vs. ADP

10. I. Energy and Life 3. How is energy released and stored? a. Energy is released by breaking the bond and removing a phosphate. ATP ADP b. Energy is stored by adding 1 phosphate to ADP. ADP  ATP

11. Energy

12. I. Energy and Life

13. I. Energy and Life 4. Most cells only have a small quantity of ATP (just a few seconds worth)! a. ATP is not efficient at storing energy for a long time. b. Cells rely on the ability to make more ATP from ADP by using energy from carbohydrates and lipids.

14. II. Photosynthesis A. Photosynthesis – when an autotroph uses carbon dioxide, water, and sunlight to make glucose, with oxygen as a byproduct.

15. II. Photosynthesis • Photosynthesis Equation – CO2+ H2O + light energyC6H12O6 + O2 Products Reactants

16. II. Photosynthesis 2. Chloroplast – organelle where photosynthesis occurs 3. Chlorophyll – Most common pigment in chloroplasts; it reflects green light a. Must be present for photosynthesis to occur.

17. II. Photosynthesis Photosynthesis has 2 stages or reactions: • Light dependent reactions • Light independent reactions (a.k.a. Calvin Cycle)

18. II. Photosynthesis B. Two Steps of Photosynthesis 1. Step One: Light Dependent Reactions a. Require light! b. Chlorophyll absorbs sunlight, which causes electronsto gain lots of energy; ATP (energy carrier) and NADPH (electron carrier) are stored for light independentreactions.

19. II. Photosynthesis NADP+ NADPH NADP+

20. II. Photosynthesis c. Water molecules broken apart into hydrogen gas and oxygen gas. - H2O + Light  O2 + H2 - Oxygenis released as a byproduct to the atmosphere.

22. II. Photosynthesis 2. Step Two: Light Independent Reactions (A.K.A. The Calvin Cycle) a. Does not require light! b. Carbon dioxide and hydrogen gas form glucose (sugar), using energy from ATP and electrons from NADPH. CO2+ H2 C6H12O6

24. II. Photosynthesis • Factors That Influence Photosynthesis Rate a. Lack of Water Example/Adaptation: Desert plants/conifers (pines) waxy coating and needle “leaves” to reduce water loss

25. II. Photosynthesis b. Temperature – Influences the activity of enzymes - Best around 35 degrees. c. Intensity of Light (varies by plant) - ExcessUV rays/sunlight can decrease photosynthesis.

26. Chapter 9: Cellular Respiration

27. Energy Review Plants—make food (sugar) through photosynthesis Animals and other organisms—get food by eating plants and animals

28. III. Cellular Respiration A. Cellular Respiration – glucose and food are broken down to make energy (ATP) in ALL organisms. 1. Occurs in the mitochondria of eukaryotes. 2. Occurs in the cytoplasm of prokaryotes.

29. III. Cellular Respiration 3. Cellular Respiration Equation – Reactants Products C6H12O6+ O2CO2 + H2O + energy

30. III. Cellular Respiration B. Two Types of Cellular Respiration 1. Aerobic Respiration – breaking down of glucose molecules into smaller pieces in the presence of oxygen to produce ATP

31. III. Cellular Respiration THREE STEPS OF AEROBIC RESPIRATION 1. Glycolysis 2. Kreb’s/Citric Acid Cycle 3. Electron Transport Chain (ETC)

32. III. Cellular Respiration 2. Three Steps of Aerobic Respiration a. Glycolysis – occurs in cytoplasm; glucose is split in half, forming a pyruvate molecule - 2ATP released - electronsreleased and carried to mitochondriaby NADH

33. III. Cellular Respiration

34. III. Cellular Respiration b. Kreb’s/Citric Acid Cycle – occurs in the mitochondria; pyruvate is split into smaller pieces - CO2gas released (we breathe it out) - 2ATP released - electronsreleased and stay in mitochondria

35. Cellular Respiration FAD+ NAD+ FADH NADH FAD+ NAD+

36. III. Cellular Respiration c. Electron Transport Chain (ETC) – occurs in the mitochondria; electrons forced through the mitochondrial membrane - 32ATP released

37. III. Cellular Respiration - TOTAL ENERGY: 36 ATP

38. III. Cellular Respiration X 3. Anaerobic Respiration – breaking down glucose molecules into smaller pieces in the absence of oxygen to produce ATP

39. III. Cellular Respiration 4. Two Steps of Anaerobic Respiration a. Glycolysis – occurs in cytoplasm; glucose is split in half, forming a pyruvate molecule - 2ATP released - electronsreleased and carried to mitochondria

40. III. Cellular Respiration b. Fermentation – breaking down pyruvate without oxygen

41. III. Cellular Respiration Two Types of Fermentation 1. Lactic Acid Fermentation – pyruvate is broken down into lactic acid + ATP • 2 ATP release • Lactic acid builds up as in muscle cells and causes burning sensation (muscle cramping) during strenuous exercise. C-C-C + NADH  H-C-C-C + ATP + NAD+ pyruvate e’ carrier  lactic acid energy carrier

42. III. Cellular Respiration • AlcoholicFermentation – pyruvate is broken down into alcohol, carbon dioxide, and ATP in yeast and bacterial cells -2 ATP released - Used in making bread and beer C-C-C + NADH  C-C-OH + CO2 + ATP Pyruvate + e’ carrier alcohol + carbon + energy dioxide

43. Cellular Respiration Digestion Glycolysis Eat Oxygen is present No oxygen is present Aerobic respiration Fermentation (anaerobic respiration) Citric acid cycle In yeast In animals Electron transport chain Alcoholic fermentation Lactic acid fermentation

44. Cellular Respiration _______ ________ ____________ ____________________ ____________________ __________________ __________ _____________________ __________________ _______ ________ ________________________ ____________________ ____________________

45. Photosynthesis vs. Respiration food synthesized food broken down requires energy produces energy Chloroplast mitochondria/cytoplasm Only autotrophs Autotrophs and heterotrophs (all living cells)