1. Photosynthesis and Respiration

2. Energy and ATP ATP –Adenosine triphosphate –Adenine, 5-carbon sugar, 3 phosphate groups ADP –Adenosine diphosphate –Adenine, 5-carbon sugar, 2 phosphate groups

3. ADP and ATP Storing energy –When a cell has energy available, it can store small amounts by adding a phosphate group to ADP, producing ATP Releasing energy –Breaking bonds between the 2 nd and 3 rd phosphate groups –Powers several cellular activities Active transport, protein synthesis, muscle contraction

4. Photosynthesis Method of converting sun energy into chemical energy usable by cells Autotrophs utilize this process –Photoautotrophs- light –Chemoautotrophs- chemicals Equation 6CO 2 + 6H 2 O + light → C 6 H 12 O 6 + 6O 2

5. Chloroplast

6. Electron Carriers Carrier molecule- a compound that can accept a pair of high-energy electrons and transfer them along with most of their energy to another molecule –Process: electron transport –Molecule: electron transport chain

7. NADP+: NADP+ accepts and holds 2 high- energy electrons along with H+ When this occurs it becomes NADPH NADPH can then carry high-energy electrons to chemical reactions elsewhere

8. Light-Dependent Reactions Require light Produce oxygen gas Convert ADP and NADP into ATP and NADPH

9. Light-Dependent Reactions 1.Pigments in photosystem II absorb light 2.Energy is absorbed by electrons which are passed on to electron transport chain -Electrons come from breaking bonds between water molecules -Create 2 electrons, H+ ions, and oxygen

10. Light-Dependent Reactions 3. Electrons move through electron transport chain –from photosystem II to photosystem I –Energy is used to transport H+ ions from stroma to inner thylakoid 4. Pigments in photosystem I use energy from light to reenergize the electrons –NADP+ picks up high energy electrons and H+ ions –Becomes NADPH

11. Light-Dependent Reactions 5. H+ ions are continuously pumped into thylakoid membrane –Inside= positively charged; outside= negatively charged –Difference in charges provides the energy needed to make ATP 6. ATP synthase- protein in membrane –Spins like a turbine –Allows H+ to cross membrane –ATP synthase binds ADP and a phosphate group together to produce ATP

13. Light-Independent Reaction Calvin Cycle Uses ATP and NADPH to produce high- energy sugars Does not require light

14. Calvin Cycle 1.6 CO 2 molecules enter cycle –Combine with 6 5-carbon molecules –Result = 12 3-carbon molecules 2. 3-carbon molecules are converted into higher-energy forms (energy from ATP and NADPH) 3. 2 3-carbon molecules are removed from cycle –Used to produce sugars, lipids, amino acids, etc.. For metabolism and growth of plant

15. Calvin Cycle 4. Remaining 10 3-carbon molecules are converted back to 6 5-carbon molecules –Combine with 6 new carbon dioxide molecules to begin the next cycle

16. Factors affecting Photosynthesis Water –Lack of water can slow or even stop photosynthesis –Desert plants have waxy coating to reduce water loss Temperature –Enzymes function at particular temp ranges Intensity of Light –Increasing light increases rate of photosynthesis –There is a maximum rate of photosynthesis

17. Cellular Respiration Breakdown of glucose to produce energy –1g of sugar releases 3811 calories of heat energy –Calorie- amount of energy needed to raise the temp of 1g of water 1˚ Celsius 6O 2 + C 6 H 12 O 6 → 6CO 2 + 6H 2 O + energy Steps: –Glycolysis –Krebs Cycle –Electron Transport Chain

18. Glycolysis Process in which one molecule of glucose is broken in half, producing 2 molecules of pyruvic acid (3-carbon compound) In cytoplasm 2 ATP → 4 ATP NAD+ = electron carrier –Accepts 4 high-energy electrons –Becomes NADH

19. Glycolysis Energy yield is small but happens very fast Does not require oxygen Problem: NAD+ molecules fill up with electrons; without NAD+ ATP production stops

20. Fermentation Releases energy from food molecules by producing ATP in the absence of oxygen –Anaerobic- not in air 2 main types –Alcoholic fermentation –Lactic acid fermentation Convert NADH to NAD+ –Allows glycolysis to continue producing a steady supply of ATP

21. Alcoholic Fermentation Pyruvic acid + NADH → alcohol + CO 2 + NAD+ Causes bread dough to rise Yeast in dough runs out of oxygen, begins fermentation which produces CO 2

22. Lactic Acid Fermentation Pyruvic acid + NADH → lactic acid + NAD+ Produced in muscles during rapid exercise when the body cannot supply enough oxygen to the tissues Some unicellular organisms produce lactic acid as a waste product –Cheese, yogurt, buttermilk, sour cream –Pickles, sauerkraut

23. Krebs Cycle Pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions Aerobic- requires oxygen AKA citric acid cycle – because citric acid is the first compound produced In mitochondrion

24. Krebs Cycle

25. Pyruvate Oxidation: –Pyruvic acid enters mitochondrion –A carbon atom is removed to form CO 2 –The other 2 carbon atoms are joined to coenzyme A to form acetyl-CoA A. Acetyl-CoA adds to a 4-carbon molecule producing a 6-carbon molecule called citric acid

26. Krebs Cycle B.-Citric acid is broken down to produce a 5-carbon chain - CO 2 is released - electrons transferred to energy carriers C.- 5-carbon chain is broken down into a 4 carbon chain - CO 2 is released - ATP is produced D. – 4 carbon chain is ready to accept acetyl CoA to start cycle all over - FAD is converted to FADH 2 - NAD+ is converted to NADH

27. Electron Transport Chain Uses high-energy electrons from the Krebs cycle to convert ADP to ATP In mitochondrion

28. Electron Transport Chain A.-NADH and FADH 2 are passed along ETC and transfer their electrons down ETC Eukaryotes: membrane of mitochondrion Prokaryotes: cell membrane –H+ ions are transferred to intermembrane space B.-electrons from ETC combine with H+ ions and oxygen to produce H 2 O

29. Electron Transport Chain C. Energy is used to transport of hydrogen ions by 2 high-energy electrons –H+ ions build up in the intermembrane space making it positively charged –The other side of the membrane is negatively charged

30. Electron Transport Chain D.-Inner membranes of mitochondria contain ATP synthase - ATP spins when H+ ion crosses membrane - While rotating, the enzyme grabs a low- energy ADP and attaches a phosphate producing ATP

31. Totals Glucose = 2 ATP Krebs + ETC = 34 ATP Total = 36 ATP Final wastes: water and carbon dioxide