1. Global warming Since the last ice age, carbon dioxide levels have increased continually. The increase of carbon dioxide over the last 150 years has been much more dramatic going from 280 parts per million (PPM) to 400 PPM. This has had obvious effects on the global temperature averages as the ten hottest years on record occurred from 1998 to now. The ten hottest years ever were: 1. 2010 2. 2005 3. 1998 4. 2013 5. 2003 6. 2002 7. 2006 8. 2009 9. 2007 10. 2004

5. Cellular Energetics How cells obtain and use energy through the processes of photosynthesis and cellular respiration

6. IV. Cellular Energetics A. Energy - ability to do work 1. Cells use an energy-storing compound known as ATP to provide the energy to do work 2. ATP = Adenosine Triphosphate a. Energy is stored in the bonds between phosphate groups b. Energy is released when bonds are broken c. ATP becomes ADP when a phosphate is lost d. ATP is recyclable e. Cells regenerate ATP through the process of cellular respiration which is reliant on photosynthesis

7. CO 2 H2OH2O Glucose O2O2 ATP ECOSYSTEM Sunlight energy Photosynthesis in chloroplasts Cellular respiration in mitochondria (for cellular work) Heat energy 

8. 3. Obtaining energy a. a. Autotrophs – organisms capable of using a source of energy to produce food molecules from inorganic molecules in the environment i. Photoautotrophs – capture light energy ii. Chemoautotrophs – absorb other inorganic molecules to produce own food b. b. Heterotrophs – organisms that obtain energy from the consuming of other organisms

9. B. Cellular Respiration 1. 1. Autotrophs and heterotrophs must be able to release energy from the carbohydrates produced during photosynthesis 2. 2. During cellular respiration, glucose is broken down in a step- by-step process to release the energy stored in its bonds 3. 3. The energy from the breakdown of glucose is used to generate ATPs 4. 4. Chemical equation C 6 H 12 O 6 + 6O 2 ----> 6CO 2 + 6 H 2 O + ENERGY (ATP) 5. Occurs in the cytoplasm and the mitochondrion

10. NADH FADH 2 GLYCOLYSIS Glucose Pyruvate CITRIC ACID CYCLE OXIDATIVE PHOSPHORYLATION (Electron Transport and Chemiosmosis) Substrate-level phosphorylation Oxidative phosphorylation Mitochondrion and High-energy electrons carried by NADH ATP CO 2 Cytoplasm Substrate-level phosphorylation

11. 6. 6. Reactions a. Glycolysis i.Takes place in the cytoplasm ii.The initial splitting of a glucose molecule iii.Produces two pyruvates iv.Process requires energy (2 ATP) to break apart glucose and produces 4 ATP v.Breaking of bonds releases energized electrons which are accepted by a molecule known as NAD + vi.NAD + is converted to NADH to carry electrons to the electron transport chain in the mitochondrion vii.If oxygen is present, the pyruvates can enter the mitochondrion (aerobic) viii. If oxygen is absent, the pyruvates will remain in the cytoplasm (anaerobic)

12. b. Krebs Cycle i.Takes place in the mitochondrion ii.Two pyruvates enter the mitochondrion and are further broken down to release energy iii.As pyruvate is gradually broken down, carbon dioxide is released as a waste product and released electrons are accepted by more NAD + and an additional molecule known as FAD iv.Produces 1 ATP for every cycle (2 ATP total)

13. c. Electron Transport Chain i.Takes place in the inner mitochondrial membrane ii.Energized electrons from the broken bonds of glucose and pyruvate provide the energy to produce ATPs iii.NADH and FADH 2 transfer electrons to an ETC in the inner mitochondrial membrane iv.Energy from the electrons activates proton pumps, building a proton concentration gradient across the membrane v. Protons pass through ATP synthase, a tranport protein/enzyme that produces ATP vi.As protons pass through, ADP is converted into ATP vii.Produces up to 34 ATP d. Overall process produces a total of 36 – 38 ATP

14. Intermembrane space Inner mitochondrial membrane Mitochondrial matrix Protein complex Electron flow Electron carrier NADH NAD + FADH 2 FAD H2OH2O ATP ADP ATP synthase H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+  P 1 2 O2O2 Electron Transport Chain Chemiosmosis. OXIDATIVE PHOSPHORYLATION + 2

15. H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ O2O2 H2OH2O P ATP NADH NAD + FADH 2 FAD RotenoneCyanide, carbon monoxide Oligomycin DNP ATP Synthase 1 2  2 ADP  Electron Transport Chain Chemiosmosis

16. 7. Fermentation - Breaking down glucose without oxygen a.Occurs in the cytoplasm b.Otherwise known as anaerobic respiration c.Begins with glycolysis d.Only produces 2 ATP e.Purpose is to regenerate NAD+ f.Two types i. i. Lactic acid fermentation A. Pyruvate is converted into lactic acid B. Occurs in muscle cells ii.Alcoholic fermentation A. Pyruvate is converted to ethyl alcohol B. Occurs in yeast cells

17. C. Photosynthesis 1. 1. Conversion of sunlight energy into chemical energy stored in the bonds of carbohydrates and other organic molecules 2. 2. Chemical equation light 6CO 2 + 6H 2 O ----> C 6 H 12 O 6 + 6O 2

18. 3. Occurs in the chloroplast a. Thylakoid – photosynthetic membrane disk b. Granum – stack of thylakoids c. Stroma – space between the thylakoids and the outer membranes of the chloroplast 4. Pigments – substance capable of absorbing and reflecting light energy a. Chlorophylls – primary pigment b. Carotenoids c. Xanthophylls

20. 5. 5. Reactions a. Light reactions i. i. Capture of sunlight energy to produce temporary energy- storing compounds (ATP and NADPH) ii. ii. Occurs in the thylakoids iii. iii. Light is absorbed by photosystems – clusters of pigment molecules in the thylakoids iv. iv. Electrons in pigment molecules are “excited” to higher energy levels

21. 5. Reactions a. Light reactions v. “Excited” electrons are passed along a series of membrane proteins known as the electron transport chain (ETC) in the thylakoid membrane vi. Energy from electrons is used to generate ATP - Energy from the electrons activates proton pumps, building a proton concentration gradient as hydrogen ions (protons) are pumped across the membrane - Protons pass through ATP synthase, a transport protien/enzyme that produces ATP - As protons pass through, ADP is converted into ATP vii. Electrons are eventually passed to an energy-storing molecule known as NADPH viii. Water is split to replenish electrons in pigment molecules ix. As water splits, electrons are donated to chlorophyll and oxygen gas is released

24. 5. Reactions b.Dark reactions i.Otherwise known as the Calvin Cycle ii.Energy from the ATP and NADPH produced in the light reactions is used to produce organic molecules from carbon dioxide iii.Occurs in the stroma