1. ATP, Photosynthesis, and Cellular Respiration: Energy in a Cell

2. I. Background information A. What is energy? --the ability to do work B. Why is it needed? --Cells need energy to maintain homeostasis and carry out life functions.

3. C. Heterotrophs get energy from _______. Ex: animals, fungi, some protists, some bacteria D. Autotrophs get energy by __________. Ex: plants, some protists, some bacteria

4. E. The chemical bonds in food are broken down to release the chemical energy stored in them. F. However, NOT all of the energy is used at once. Some of it has to be stored.

5. ATP II. ATP—adenosine triphosphate— an energy-storing molecule phosphate bonds ATP is made of: 3 phosphates 1 sugar 1 adenine

6. A. Energy is stored in the phosphate bonds. B. Energy is released when the phosphate bonds are broken.

7. C. When energy is released from ATP, a phosphate is released and ADP is left. ADP D. ADP—adenosine diphosphate ADP is made of: 2 phosphates 1 sugar 1 adenine

8. Let’s look at this reversible reaction in 3 different ways…

9. ATP ADP + phosphate + energy ATP energy ADP + phosphate

10. ++ energy ADP + phosphate + energy ATP

11. III. Photosynthesis photo—means light synthesis—means to make *Photosynthesis is the process in which autotrophs use light energy to make food.

12. Chemosynthesis bacteriainorganic compounds *Chemosynthesis is a similar process in which some bacteria use inorganic compounds to make food. chemo—means chemical

13. *Equation for Photosynthesis: CO 2 + H 2 O light energy C 6 H 12 O 6 + O 2 carbon dioxide + water light energy glucose + oxygen Note: Chemical equation at top Word equation on bottom

14. A. Where does photosynthesis take place? chloroplasts chlorophyll 1. in the chloroplasts, which contain the green pigment chlorophyll leaves 2. In plants it mainly occurs in the leaves.

15. B. Requirements for Photosynthesis: 1. water (H 2 O) 2. carbon dioxide (CO 2 ) 3. sunlight (or light energy) 4. chlorophyll (which is already present in the plant)

16. Stoma (stomata-plural) of a leaf

17. C. Products: glucose 1. Main Product—glucose (C 6 H 12 O 6 ) oxygen 2. Waste Product or by-product— oxygen (O 2 )

18. D. Two Stages: 1. Light or light-dependent reactions --involves Photosystem I and II a. Chlorophyll absorbs light energy and uses it to split water. b. photolysis—splitting of water c. Take place in the grana or thylakoids

19. Chloroplast Structure

20. 2. Dark or light-independent reactions (also called Calvin Cycle or Calvin-Benson Cycle) a. Do NOT require light! b. Glucose is produced. c. Take place in the stroma

21. Overview of Photosynthesis

22. IV. Cellular Respiration *a process in which organisms (heterotrophs AND autotrophs) break down food to release energy *There are 2 types of respiration: aerobic anaerobic

23. *Equation for Aerobic Respiration: C 6 H 12 O 6 + O 2 CO 2 + H 2 O + ATP glucose + oxygen carbon dioxide + water + energy

24. A. Aerobic Respiration 1. Most common type Requires oxygen 2. Requires oxygen 36 ATP’s 3. Produces 36 ATP’s of energy for each molecule of glucose mitochondria 4. Takes place in the mitochondria

25. Mitochondrion Structure

26. Mitochondrion

27. 5. Aerobic respiration involves 3 processes: a. glycolysis—splitting of glucose 2 ATP’s cytoplasm -produces 2 ATP’s by itself -occurs in the cytoplasm b. citric acid cycle (Krebs cycle) c. electron transport chain

30. B. Anaerobic Respiration Does NOT require oxygen 1. Does NOT require oxygen 2 ATP’s total 2. Produces only 2 ATP’s total cytoplasm 3. Takes place in the cytoplasm fermentation 4. Also called fermentation Begins with glycolysis 5. Begins with glycolysis

31. C. Types of Fermentation (Anaerobic Respiration): Lactic acid fermentation 1. Lactic acid fermentation— a. takes place in animals Lactic acid b. Lactic acid is the waste product. c. Lactic acid builds up in muscles, causing muscle fatigue.

32. Alcoholic fermentation 2. Alcoholic fermentation— a. takes place in some microorganisms such as yeast Ethyl alcohol carbon dioxide b. Ethyl alcohol and carbon dioxide are the waste products. c. Process used in making alcoholic beverages

33. D. Both types of Respiration: Main product=energy (ATP) E. For Aerobic: Waste products=carbon dioxide and water

34. F. Contrasting Table CategoryPhotosynthesisRespiration OrganelleChloroplastMitochondrion EnergyRequiredProduced Glucose (food)ProducedRequired OxygenProducedRequired Carbon dioxideRequiredProduced