1. Cellular Respiration Honors Biology

2. What is Cellular Respiration? The process of converting food energy into ATP energy C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O + 36 ATP

3. Why are both Photosynthesis and Cell Respiration important to Ecosystems? Light is the ultimate source of energy for all ecosystems Chemicals cycle and Energy flows Photosynthesis and cellular respiration are opposite reactions

4. Why do plants need both chloroplasts and mitochondria? Chloroplasts use energy from the sun to make glucose Mitochondria convert glucose to ATP—the energy currency of the cell

5. Why use ATP energy and not energy from glucose? Breaking down glucose yields too much energy for cellular reactions and most of the energy would be wasted as heat. 1 Glucose = 686 kcal 1 ATP = 7.3 kcal 1 Glucose → 36 ATP How efficient are cells at converting glucose into ATP? –38% of the energy from glucose yields ATP, therefore 62% wasted as heat.

6. Cellular Respiration is a Redox Reaction C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O Oxidation is the loss of electrons or H + Reduction is the gain of electrons or H + (Oxidation) (Reduction)

7. Cellular Respiration is a Redox Reaction Glucose is oxidized when electrons and H + are passed to coenzymes NAD + and FAD before reducing or passing them to oxygen. Glucose is oxidized by a series of smaller steps so that smaller packets of energy are released to make ATP, rather than one large explosion of energy.

8. Cell Respiration can be divided into 3 Parts: 1)Glycolysis 2)The Krebs Cycle 3) The Electron Transport Chain

9. Where do the 3 parts of Cellular Respiration take place? Glycolysis: –Cytosol The Krebs Cycle: –Matrix Electron Transport Chain and Cheimiosmotic Phosphorylation: –Cristae

10. Parts of the Mitochondria

11. Anaerobic Respiration (no oxygen required, cytoplasm) Glycolysis (substrate level) Glucose  4 ATP (Net 2 ATP) 2 ATP2 NADH 2 Pyruvate Aerobic Respiration (oxygen required, mitochondria) Oxidation Of Pyruvate 2 Pyruvate  2 CO 2 2 NADH 2 Acetyl CoA Krebs Cycle (substrate level) 2 Acetyl CoA  4 CO 2 2 ATP 6 NADH 2 FADH 2 Electron Transport Chain (chemiosmotic) 10 NADH  32 ATP 2 FADH 2 6 H 2 O 6 O 2 Total ATP Production in Cellular Respiration: 36 ATP produced

12. Glycolysis Glucose (C 6 ) is split to make 2 Pyruvates (C 3 ) –1 st : ATP energy used to phosphorylate glucose (stored energy) –2 nd : phosphorylated glucose broken down into two C 3 sugar phosphates –3 rd : the sugar phosphates are oxidized to yield electrons and H + ions which are donated to 2NAD + → 2NADH 2NAD + → 2NADH –4 th : The energy from oxidation is used to make 4 ATP molecules (net 2 ATP) Glucose  2 Pyruvate 2 ATP4 ATP (Net 2 ATP) 2 NAD+2 NADH

13. Glycolysis Glucose (C 6 ) is split to make 2 Pyruvates (C 3 ) An enzyme transfers phosphate to ADP making ATP Glycolysis produces very little ATP energy, most energy is still stored in Pyruvate molecules. Glucose  2 Pyruvate 2 ATP4 ATP (Net 2 ATP) 2 NAD+2 NADH

14. Oxidation of Pyruvate /Transition Reaction (After glycolysis, before the Krebs Cycle) When Oxygen is present, 2 Pyruvates go to the matrix where they are converted into 2 Acetyl CoA (C 2 ). 2CO2 are released while the 2 pyruvate get converted 2 NADH ’ s carry electrons and hydrogens to the Electron Transport Chain Coenzyme A assists the process of creating Acetyl CoA 2 Pyruvate  2 CO 2 2 NAD+2 NADH 2 Acetyl CoA

15. The Krebs Cycle / Citric Acid Cycle Overview - -Two Turns of the Krebs Cycle are required to break down both Acetyl Coenzyme A molecules. - -Break down and oxidize each Acetyl Co (2-C ’ s) to release 2 CO 2 and yield electrons and H + ions to - -3 NAD + + 1 FAD → 3NADH + 1FADH 2. This yields energy to produce 1 ATP (in each turn of the cycle) 2 Acetyl CoA  4 CO 2 2 ADP2 ATP 6 NAD+6 NADH 2 FAD 2 FADH 2

16. The Krebs Cycle / Citric Acid Cycle Steps in Matrix of Mitochondria - -Oxaloacetate (4C) combines with Acetyl CoA (2C) to form Citric Acid (6C) - -NAD+ and FAD molecules are reduced as they pick up electrons and hydrogens - -An enzyme combines a phosphate group with ADP to form ATP - -After CO2, NADH, FADH2, and ATP is released, Oxaloacetate is recycled back into the cycle to combine with another Acetyl CoA - -**Remember the cycle occurs twice! (once for each Acetyl CoA molecule) ** Produces some chemical energy in the form of ATP but most of the chemical energy is in the form of NADH and FADH 2 which then go on to the Electron Transport Chain. 2 Acetyl CoA  4 CO 2 2 ADP2 ATP 6 NAD+6 NADH 2 FAD2 FADH 2

17. The Electron Transport Chain NADH and FADH 2 (carrying hydrogens and electrons) go to the Electron Transport Chain. NADH and FADH 2 release electrons to carriers/proteins embedded in the membrane of the cristae. As the electrons are transferred, H + ions are pumped from the matrix to the intermembrane space up the concentration gradient. 10 NADH  32 ATP 2 FADH 2 H 2 O Oxygen http://vcell.ndsu.nodak.edu/animations/etc/movie.htm

18. The Electron Transport Chain Electrons are passed along a series of 9 carriers until they are ultimately donated to an Oxygen molecule. ½ O 2 + 2 electrons + 2 H + (from NADH and FADH 2 ) → H 2 O. The high H+ concentration in the inner membrane space creates a gradient and is used to produce ATP 10 NADH  32 ATP 2 FADH 2 H 2 O Oxygen http://vcell.ndsu.nodak.edu/animations/etc/movie.htm

19. ATP Synthase –The H+ in the intermembrane space have a high concentration –So they move back across the inner mitochondrial membrane and into the matrix through a molecule called ATP Synthase –As ATP Synthase turns and H+ ions pass through, it changes shape and the enzyme makes ATP

20. Review ATP Production: 1)Glycolysis → 2 ATP 2) Oxidation of Pyruvate → No ATP 3) The Krebs Cycle → 2 ATP 4) The Electron Transport Chain - Each NADH produces 2-3 ATP so 10 NADH → 28 ATP - Each FADH 2 produces 2 ATP so 2 FADH 2 → 4 ATP so 2 FADH 2 → 4 ATP Total = 36 ATP Total = 36 ATP

21. Review ATP Production: 1 Glucose = 686 kcal 1 ATP = 7.3 kcal 1 Glucose → 36 ATP How efficient are cells at converting glucose into ATP? –38% of the energy from glucose yields ATP, therefore 62% wasted as heat (used to maintain body temperature or is dissipated) –Ex. Most efficient Cars: only 25% of the energy from gasoline is used to move the car, 75% heat.

22. All Types of Molecules can be used to form ATP by Cell Respiration: Proteins, Carbohydrates, and Lipids must first be broken down into their monomers and absorbed in the small intestine. Monomers may be further broken down into intermediate molecules before entering different parts of Cell respiration to ultimately form ATP.

23. Anaerobic Respiration: Fermentation If there is NO oxygen, then cells can make ATP by Fermentation Without oxygen, The Krebs Cycle and the Electron Transport Chain do not operate, but glycolysis still occurs. Glucose → Pyruvate → Lactate NAD + Glycolysis 2 NADH Reduction Rxn or 2 ATP Alcohol + CO 2

24. Anaerobic Respiration: Fermentation Fermentation yields a net gain of 2 ATP for every 1 Glucose. (Inefficient) Two Forms of Fermentation: Lactic Acid Fermentation (animals) Alcohol Fermentation (yeast and some bacteria)

25. PYRUVIC ACID ___________ OXYGEN 2 kinds of fermentation & ANAEROBIC Alcoholic Lactic acid WITHOUT O2

26. + → + + ALCOHOLIC FERMENTATION PYRUVIC ACID ALCOHOL Happens when yeast makes bread dough rise CO 2 bubbles make _____________ in bread Alcohol _______________ during cooking CO 2 NAD + http://www.deliciousdelicious.com/archives/herb%20bread%201.jpg air spaces evaporates

27. + → + + ALCOHOLIC FERMENTATION PYRUVIC ACID ALCOHOL Happens when ___________ make _______ or ____________ make ______ CO 2 NAD + http://www.firstpath.com/images/alcohol.jpg yeast beer bacteriawine

28. + → + LACTIC ACID FERMENTATION PYRUVIC ACID LACTIC ACID Happens in _____________ during ____________when body can’t get oxygen to tissues fast enough. Lactic acid builds up in muscles causing soreness NAD + http://www.miranda.com/library.en/Images/Pictures/girls-runners.jpg exercise muscles

29. + → + LACTIC ACID FERMENTATION PYRUVIC ACID LACTIC ACID Happens when bacteria are used to make foods and beverages like: __________________________ NAD + http://chronicle.augusta.com/images/headlines/032200/DANNON_YOGURT.jpg http://www.reillydairy.com/natural_cheese.html yogurt, cheese, buttermilk, & sour cream, pickles, saurkraut, and kimchi

30. WITHOUT OXYGEN, PYRUVIC ACID ___________ and all the _______ carriers get full. Eventually glycolysis will WHY DO FERMENTATION? WHY NOT JUST KEEP MAKING ATP USING GLYCOLYSIS? builds up NAD +

31. + → + + FERMENTATION HAPPENS so cells can ____________________ needed to keep glycolysis going PYRUVIC ACID ALCOHOL → CO 2 NAD + REGENERATE the NAD + LACTIC ACID NAD + → You get the NAD + carriers back ______